Kohlrabi??
Grows great what does one do with it?
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My parents are from Hungary.  My mom always put it in soup.  Peel it and cube it first.  That size it is very likely too 'woody' inside to eat.  The chickens and turkeys will love the leaves!

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Very woody. Off to the compost pile with most but going to see if they will produce a seed head and propagate.

Holy crap.

I was cleaning my beds and used a paint bucket filter keep the crap from getting back in the beds.
I need better filtration on an on going basis.

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I put a nylon mesh bag in the pipe from the outflow of the fish tank to catch some of the bigger poop and stuff.  By the end of the last season I still ended up with quite a bit of sediment where the pipe feeds into the grow bed.  Not a big deal, but I will have to shovel out some of the expanded shale in that corner, put it on plastic screening, and rinse it off with water.  

I've been working on a solar heating system.  I really want a hotter system this summer.  Heat makes catfish grow like crazy.

My system rework took a little longer then I planned because I ran into a problem.  I have not built many bell siphons but I should have done my research because I had designed the 3/4" bell and siphon correctly but the drain is where I got stuck.  My grow bed exits via a 2" bulkhead/piping and that did not give me the back pressure I needed to start the siphon.  My problem being I did not want to replace a 2" bulkhead with a smaller one because I would have to patch my pond liner nor did I really want to buy a ton of bushings to convert to 3/4".  I went ahead and patched the pond liner but that added a few days to the project.

While I still had my 2" pipe in place I went ahead and removed half my gravel and did a throughout cleaning.  I had lots of muck and its been a little over a year since I've maintained it. This is where water enters my grow bed.


2" exit


Once I got it cleaned out and was waiting on my patch job to dry I transferred my tilapia over to a spare 150 gallon tank and did my weight and count.  I was a little disappointed because I thought I had more fish since I knew I had live birth  late last summer and plenty of places for the young to hide.  I started with 36 that I put in the system August 2013 and my final count last week was 38 weighing in at 29.5LBS.  Out of all that time I got two freaking survivors .  I've had better luck raising miniature rabbits..  Due to keeping the fish stress level down I only took pics of my harvest.  All 12 were pretty close to a pound and just look at the beautiful colors!


Once my patch job dried I built my 3/4" siphon and 1.5" bell.  I wanted to know exactly how many gallons my grow bed would hold and I came up with 19 gallons.  My siphon was a first time go on the drain but would not break so I put in a 1/4" tube and it works fine.  I have it on a twenty minute fill and a 6 minute drain.



Due to the flood and drain I added an additional sump and tied them together with two 1.5" bulkhead fittings.  I probably did not need to do this with only 19 gallons leaving my grow bed at once and my existing sump holding twenty-five gallons but sometimes they fill up with rain water and now I will have some extra capacity.  


I recently dug an irrigation system for my yard and my one inch main goes underneath my aquaponic system so I branched up beside my spare holding tank and would like to put a float inside for automatic water refill. During our hot summers I can sometimes loose 50 gallons in a week in a half from evaporation.


Hopefully I will get better aeration in my grow bed and my growing medium will not stay as wet.  I did a 6th grade experiment with my niece last summer where we tested the same plant watered with aquaponic water and one with tap water.  It appeared that the tap water side grew better but did not have the best taste.  One of the reasons for the increase in growth could have been the soil was only watered deeply once a day and stayed dryer.  We will see what changes!

Very nice haul!

I love tilapia.  It has a nice white, flaky meat with no strong flavor.

Starting a very small training wheel system. 3 gallon tank, one Betta and some wheat grass, lettuce, and a couple of jelepeno plants.

Good deal.  Post up some pics.

Yeah, let's see some pictures!  I recommend baking or grilling the Betta since they're a pretty oily fish.

LOL OK, it's a commercial system I found at a rubbage... err..rummage store for 10 bucks. We'd 's just harvested our first lettuce out of an aerogarden, and another friend of ours... well.. she convinced me that aquaponics might be a good thing.  Here's a pic of the aquafarm, though this one isn't mine.  The one I found was a newer version with a water pump instead of a bubbler to lift water to the tray.

While sleek looking, doing any tank cleaning is an exercise in logistics.

ETA: we've had oat grass growing in this, the cats love it.  :)

A small system helps you understand the basics.  It's a really good idea.  If you look at the beginning of this thread, I made a smaller system with a 55 gallon barrel and about 25 gallons of grow bed media before basically multiplying that by 10 to a 550 gallon fish tank and 250 gallons of media.  When you have a small system, it gives you the confidence of going bigger.

Update: 05/02/2015 The Spice Must Flow

I've started the water flow on my aquaponics system.  This is year #4.

I am still going to update with Channel catfish pictures.  I had some deaths last fall and I want you to see how big the fish got.  I will get that up in another post.

As I promised, I am using a home-made solar heater with 1/2" polyethylene drip irrigation tubing.  I followed the instructions here so this is in no way my own design.  The materials total < $100.  I used 1/2" PVC tubing and a 4-way connector to make a "cross".  Then the 1/2" black polyethylene tubing is secured to it using narrow 8" zip ties.  It requires a lot of time but is pretty easy to put together and it's very low cost all things considered.

In the link posted above, the guy uses a continuous 500 foot coil to make his solar heater.  I decided to source it locally and could only get it in 100 foot sections.  So I used a connector to get 200 foot sections and then made 2 X 200 foot coils.  So the total amount of tubing is 400 feet.

I did a little experimenting today with a single coil.  



Outside temperature:   73F

Pump off/siphon action only.  There is actually siphon flow through the coil with the pump turned off.  It's amazing how much the water heated up!  The following are the water temperatures.  I measured the "IN" temperature in the 550 gallon fish tank and the "OUT" is the outflow from the 200 foot coil:

IN     52.5F
OUT  67.5F

Pump on (this was done later so water temperature in fish tank had gone up):

IN      53.6F
OUT  58.6F

With the pump on, that means the delta-T is 5 degrees F with a flow rate of about 75 gallons an hour and a total of 750 gallons in the system.
Not too shabby, but could be better.  It will be interesting to see how much this thing heats up.

I unfortunately don't have a Y connector that won't restrict flow, so I don't know how much my flow will drop once I have both coils hooked up.  It's going to
be hooked up in parallel.  If the flow is not great with the current 375 GPH (gallon per hour pump) then I'll use a 750 GPH one.  If I could get a total of 150 GPH
of flow with a delta-T of 5 degrees F on really sunny days, that would be insane.  

This really seems to be working out well but we have to remember it's a very sunny day out there and on cloudy days I'm not expecting a lot of heating.  I
have not added the bacteria yet to the system but I will do so tomorrow morning when I clean the canister filters for the indoor Channel catfish.  I am also
going to add a source of ammonia, either ammonium sulfate or urea.  This is very exciting!  Catfish grow much faster in warm water.

Also, once the system is up and running, I will be adding a UV filter ie. a device through which the water runs and uses ultraviolet light to kill everything in the
water that passes through it including bacteria (the good bacteria is not in the water but grow on surfaces including, and most importantly, on the expanded shale),
viruses, protozoa, parasitic worms, etc.  I had a terrible bacterial bloom last summer and a UV filter should wipe it out this year or prevent it from happening.

Feel free to ask questions!


Both coils:



This is not even the worst of winter.  Everything was completely covered in snow!

Looks fun And like a lot work. I'm glad I run year round.
I have thought of a solar water heater but your tube idea looks ease I think I will try it with 3/4 tubing to improve flow.

Have we determined the best food for our fish yet?
I just using a cheap pond pellet from walmart and duckweed.

For Tilapia and Catfish, I would go with Aquamax 4000.  I posted this on page 13.  These pellets do float so make sure your fish will take pellets from the surface.  I couldn't get mine  to do so reliably, so I sent the remaining food I had to delicious_bass.  Maybe he can chime in on his results.  I did try to soak the pellets for them to sink but then the fish didn't want to eat them.  I've read about that being the case before.

Here are the labels:

Lets talk about this for a minute just for fun and learning.  If your pump is 375GPH could you find out what you are currently pushing  and subtract the head loss for 1/2 poly tubing @ 400'?
 

At 360GPH it would not be recommended to run the 400' of poly tubing just by itself because of friction.  That is not taking into account the elevation head loss of the poly tubing on top of the grow bed.  It's too late and too much math

I think without a doubt I would put the bigger 750GPH pump on it and right behind the poly tubing a ten psi regulator.  I can see myself building one of these and the idea is great.  

My bell siphon is giving me trouble and I can't get the siphon to break like its supposed to.  I have tried everything I know to get it to work and it will just sit there and gurgle for 4-5 minutes then break.  I am begging to wonder if there is a certain minimum depth for one of these to work efficiently.  My stand pipe sits 4" max and I have tried building both (3/4"-1 1/2") and (1/2-1").  They both act the very same and gurgle when it gets to the bottom of my bell, even after I put a 1/4"breather tube in.  I am going to try a few more tweaks before I go back to constant.

Edit- I like how you left the zip ties on the tubing, they kind of remind me of those eye lash headlights that people but on their VW Bugs.

1) To answer the first question, and I preface this by saying I have very little education in flow dynamics, there is no head pressure since, technically, the pump sits high up in the fish tank and is above the solar heater coils and the outflow tubes from the solar heaters.  I know this because when I have only one coil connected, there was spontaneous flow, albeit very little, due to siphon action.  So the pump definitely sits above the solar coils/outflow.  With both solar heater coils connected, there is no siphon action but I would have to double check on that.  

Or by "head loss" do you mean the resistance due to the 400 feet of coils?  BTW, it's 2 X 200 feet because the coils are connected in parallel rather than series if that actually makes a difference.

2) The siphons can be extremely frustrating, especially when they don't break because now the grow bed is "dry".  I would first try to shorten the 1/4" breather tube as that would force a break in the siphon.  Can you put 1/2" breather tube?  I don't know if that would make a difference but it may.  I had to shorten my breather tube to get it to break.  

Yes, flow.  

As you know, if pipes are added in a series, the resistance is added to together so resistance increases and flow rate is reduced.

If pipes are connected in parallel, this increases the area, so resistance is reduced and flow rate increased.

This is born out by connecting the pipes in parallel and getting 120 GPH flow rate as opposed to 75 GPH from only one tube connected.  I think if I use a larger Y connector will help the flow even more so and it's on order.

I haven't even tried series as I don't think the pump would even work.  I really should try it just to see what would happen.  But I would be surprised if there was any flow at 400 feet of tubing!

375 gph .5 pipe = an 84psi drop at 200 ft and only 10psi for .75
using my pressure drop calculator app.and making some random Assumptions
so for my 11gph pump and a 400 ft run I need at least 1" tube
Off to price tubing

Yes.  I'm sure there is a sweet spot where one diameter has a benefit over the other.  One interesting problem I ran into was when disconnecting the tubing from the pump to the solar heater.  If water leaked out the inlet portion, when I reconnected the pump then I would get either no or very little flow.  The tubing became airlocked.  Not a big deal if the pump is strong enough to push out the air, but my pump is small and simply doesn't have the power to do it.  So I had to take the coils and turn them to get all the water out and then reconnect.  Alternatively, you can turn it until the inlet portion has water coming out and then reconnect.  But the point is that if you have to manipulate the coils for any reason, including moving them, it's a good thing if they are light as they become very heavy once water is in them!

I will definitely look into the 3/4" tubing as I have the 750 GPH pump that I could use for the larger diameter tubing.

I'll take a look some more at how to make those calculations with the tables.  I figured I'd put something together and see what would happen.  Not very scientific, I know.

Update:  05/10/2015  Day 8 of cycling p. 18

I found a gross error in some calculations I did a while back.



The problem with the part in blue which is on p. 13 is that the system is 775 gallons, not 225 gallons.  225 gallons is the volume of the sump tank on the right.  

Recalculating, we get the following:  (ETA:  I used 750 gallons for my calculations so I'm going to keep it that way.  It's probably closer to 775 or even 800 gallons in the whole system.)

775 750 gallon =  2,839 liters

1 ppm of a liter is 1mg so we need 2,839 liters X 1mg/liter = 2,839 mg for 1ppm in the total of 750 gallons of water.

But since we are shooting for 8 ppm, we will multiply 2,839 mg X 8 = 22,712 mg = ~ 22.7 grams of ammonia (NH₃). That will give us 8 ppm of NH3.

However, we're not using ammonia, we're using urea (and later, ammonium sulfate). For each molecule of urea hydrolyzed, we produce two molecules of ammonia when it is broken down by bacteria:

CO(NH2)2 + H2O -------------> 2NH3 + CO2

We want 22.7 grams of ammonia (NH3). Since the molecular weight of NH3 is 17 grams/mole, the amount of ammonia we need is 22.7 grams/17grams/mole = 1.33 moles.

Since the molar ratio in the above formula is urea:ammonia = 1:2 we will need only half the number of moles of urea so 0.665 (1.33 divided by 2) moles. The molecular weight of urea is 60 grams/mole. So we will need 0.665 moles X 60 grams/mole = 39.9 grams of urea dissolved in 750 gallons of water to obtain a concentration of 8 ppm (8 parts per million).

By some (other ) miscalculations, I ended up putting 28 grams in on 05/03/2015, the day I started cycling with added ammonia (urea) and bacteria.  The water flow actually started a day or two earlier, but I didn't add bacteria until 05/03/2015.  That day, I also put in the washings from my 2 indoor canister filters, a couple of dirty sponges from a friend's aquarium, and some expanded shale that I was using as media in one of the canister filters.  The latter expanded shale already had bacteria on it but amounted to at most about a gallon of media when added to some other mesh bags of expanded shale I had in the 75 gallon indoor Channel catfish tank.  I dug down in the grow bed and put the bacteria-covered expanded shale throughout the 250 gallon expanded shale grow bed to maximize contact.  I really felt good about the bacterial load in the outdoor aquaponics system.  Quick point:  Many/most bacteria have the enzyme urease which breaks urea down into ammonia and carbon dioxide.

After a few days, I measured the ammonia level and it came back at 1 ppm.  Hmm.  I added another 28 grams of urea and got a little more of a bump in ammonia and then also found that nitrite was positive, but after a few days ammonia dropped back down.  I think part of the urea gets bound to minerals in the expanded shale which may artificially decrease the concentration in the water and, of course, some of the ammonia was converted into nitrite.  Ammonia had dropped to about 0.75 ppm and nitrite was between 2 and 5 ppm, so we'll call it 3.5 ppm.  It's difficult to convey the color with a photo as the color may appear different in the photo:



I know they say that it takes 4 to 6 weeks to cycle a system, but my experience is that it takes less time than that.  One of my theories is that the expanded shale has a much greater exposure to oxygen and I think this increases the bacterial growth on the expanded shale.  In an aquarium, you are limited by the lower oxygen saturation of the warm water and the only oxygen that gets to the filtration media is what is dissolved in the water.  In a flood and drain type system, the water siphons out of the entire 250 gallon expanded shale grow bed and exposes all the shale to oxygen from the air.  This happens every 13 minutes (on average).  Well, that's my theory about that.

Two days ago, 05/08/2015, I decided to add some ammonium sulfate and bump the ammonia level again and then measure the ammonia and nitrite levels but this time I used ammonium sulfate since I wanted to have a more direct ammonia addition.  The calculations were as follows:

Since there was already some ammonia in the system in the form of urea, I decided to add enough for 5 ppm, so we multiply 2,839 mg X 5 = 14,195 mg = ~ 14.2 grams of ammonia (NH₃). That will give us 8 ppm of NH3.

We want 14.2 grams of ammonia (NH3) in . Since the molecular weight of NH3 is 17 grams/mole, the amount of ammonia we need is 14.2 grams/17grams/mole = 0.835 moles.

Since the molar ratio in the above formula is ammonium sulfate:ammonia = 1:2 we will need only half the number of moles of ammonium sulfate so 0.4175 (0.835 divided by 2) moles. The molecular weight of ammonium sulfate is 132 grams/mole. So we will need 0.4175 moles X 132 grams/mole = 55.11 grams of ammonium sulfate dissolved in 750 gallons of water to obtain an additional concentration of 5 ppm (5 parts per million).

I checked the levels of ammonia and nitrite and nitrate.  The ammonia was at 4 ppm and nitrite at 5 ppm but I also measured nitrate!  At this point, 6 days into cycling, I found a surprising amount of nitrate, 40 to 80 ppm so about 60 ppm.  You're going to say that's an awful lot of nitrate for so little ammonia added so far (urea X 2 and then ammonium sulfate), but remember that ppm go by weight ie. weight of the substance over the weight of the water it's dissolved in.  When NH₃ is oxidized, you are adding 3 oxygen atoms and most of the weight of the nitrate ion is from that added oxygen (NO₃-).



So, there you have it.  I have ammonia, nitrite and nitrate.  I think at this point I'm going to follow the levels of ammonia, nitrite and nitrate.  Once all the ammonia and nitrite are gone, I will add the 2 goldfish to the fish tank as well as some sodium chloride/salt as a protection against a nitrite spike.  IIRC, I have cycled the system in as little as 2 weeks in the past.  I'm a little at a loss to explain it entirely, but I do believe the high oxygen levels I noted above as well as the heavy bacterial inoculation are the likely answers as to why I seem to shave off so much time.  

I'll post about heating in the system in another post as well as pictures of the fish from last year showing how much they grew (the largest two died from ich last fall but I have weights and photos).  I have temperatures from when I started cycling and I have been going from around 55 F in the AM to about 66 F in the PM.  So I have a reasonably good temperature in the system considering it is outdoors and here in NH.  I checked this morning's temperature and it started considerably higher at 62 F but it was warmer last night.  I think the highs today are in the low 80's.  My peak temperature so far was 68 F.  We may break that record today!

Also, once the system is up and running with the goldfish, I am going to add a 55 Watt UV filter/clarifier to kill any bacteria, virus, protozoa or other parasite in the water.  It will also kill any other insect eggs/larvae such midge.

ETA:  I'm trying to do new things with my system in part because it is a tacked thread and I don't want it to become stale.  I'm really glad others have been posting as well, especially since they have warm water systems which can support Tilapia which I will likely never even attempt.

The two new things are, of course, for this season:

1) Solar heating system:  This will hopefully mean significantly higher temperatures and increased growth rates.  It can also be added to a warm-weather Tilapia system to extend the growing season.

2) UV sterilizer/clarifier:  This will hopefully prevent an ich infestation or a bacterial bloom like I had last season.  

Minor Update:

I got a peak temperature today of 73 F!  So it went from 62 F to 73 F.  Not bad.  I can't help but think this will make the system cycle faster.

I can't forget that it's still May in New Hampshire.  Looking at the forecast, we are getting days with highs in the 60's and 70's, so I'm not expecting
highs like today of 73 F.  If the water can stay in the low 60's at least for the next couple of weeks, I'll be happy.  

I'm also working on electronic control of the solar heater pump with a friend where the pump shuts off when the output temperature of the solar heater
falls below the input temperature.  Since there is still a slight siphon action even when the pump is off, the temperature probe could be set up to then
turn the pump back on if the output temperature becomes higher than the input temperature.  I'd also put a maximum temperature cut-off so it doesn't
cook the system such as the middle of summer, maybe around 85 F.  The latter may not ever happen, but I wouldn't be surprised.

ETA:  I didn't bother with ammonia/nitrite/nitrate levels today.  Like I posted earlier, I think it's fine to check every couple of days.  It's probably even fine
if you do it every 5+ days since there are no fish to worry about.  I'm hoping the ammonia and nitrite drop to zero in the next 10 days.  I'd really like to get
the fish in there as soon as possible given the short growing season.  It's nice to have the goldfish to put in first though I wouldn't be happy if they died.  As
long as the water conditions are OK, though, that shouldn't happen.

Minor Update:

Today was the first day where the temperature ended at a lower number than it started.  I think I may post the temperatures on the first page in the first post, including the maximum and minimum air temperatures.  It started at 66 F and ended at 64 F.  Tomorrow it's supposed to go up to 80 F so it will likely go back up again.

I measured the levels today (I can't help myself!):

Ammonia:  Zero

Nitrite:  Zero

Nitrate:  Between 60 and 80mg/L

So there's definitely some bacterial action going on.  I think I may hit it again with 5mg/L of ammonia tonight.  One thing you have to be careful of is accidentally starving your bacteria.  That's a big no-no.  So for that reason alone, maybe I'll be checking more frequently.  Who knows, I may be putting the goldfish in by Sunday.  I really want to be careful and not rush things, but it the results indicate that there is good bacterial activity, there's no point in delaying.  

ETA:  I just added 55.1 grams of ammonium sulfate to the 750 gallons of water which is 5 ppm (parts per million) of ammonia.  It will be interesting to see how much nitrite builds up.  Usually there is a bottle-necking of the second reaction of converting nitrite to nitrate since that step is slower and the Nitrobacter bacteria that are responsible for it grow more slowly than Nitrosomomas which converts ammonia to nitrite.  


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Sounds like you will be adding fish soon and you got the system cycling down!  I wish I had something new to post or rework in my home system but I just cant bring myself to do it with possibly moving in a year.  


What ideas do you have for the temperature control box?  We use the Ranco ETC on our 1000w heaters and they are really simple.  They are not made for outdoors but ours is going on 4 years old that lives in a humid greenhouse.  You could always wire it inside a plastic tool box and cut out and mount an outlet box to it for an outdoor location.  I do know they can be wired for multiple probes to take an average reading.  Im not using mine now if you want me to box it up and mail it to you to try out.

Thank you for the offer.  I'll keep it in mind.  The plan for now is to construct something ourselves but that may not work out.  

Yeah, you're better off focusing on your move than fooling around with system modification.  

I think you're absolutely right that I am close to getting fish in there.  I did a heavy job of inoculating the system with Nitrosomonas and Nitrobacter bacteria.  I'm still a little surprised that it has gone this quickly.  I will check levels tomorrow and if all the ammonia and nitrites are gone, I'll likely do a full water change on Thursday and then transfer the goldfish into the system on Friday.  I have an acquaintance who gave me the 550 gallon tank (which started this whole project) and he may come over on the weekend.  Either way, I'll start putting catfish in it either Friday with the goldfish or Saturday.  I'm going to load them in there slowly, maybe a couple every day and measure for any nitrite spike.  I'm not really worried about an ammonia spike as I will be careful about slowly increasing the feedings.
 

Quick Update:

I added 55.1 grams of Ammonium Sulphate or 5 ppm of ammonia (NH₃) to my system 48 hours ago (2 nights ago or on 05/11/2015) and the results were:

1) Ammonia is zero.

2) Nitrite is zero.

3) Nitrate is at the top of the scale which is 160 mg/L.

This means that the bacteria are chewing through large amounts of ammonia like crazy, and there is no bottle-necking at the nitrite
stage which means the Nitrobacter population is robust.  

So I think I'm all set to drain the system tomorrow and refill it with fresh water.  This is very exciting.  I may put goldfish in it on
Friday as long as the water temperature is OK.  Well water is around 52 F so if I heat it for 24 hours from Thursday to Friday, I should
be good to go with adding the goldfish on Friday, then catfish over the ensuing days!

Thats good news and good job on cycling.  Are you draining it due to the nitrates?

Yes, absolutely.  There's no reason not to start fresh.  

I'm not sure if I should fool around with the placement of the solar heater.  One option is to put them over the sump tank, but then
I would not have the siphon action that I have now.  I will think about it some more.  

ETA:  The ambient temperature outside was 58 F today and that's what I started with water temperature.  By the end of the day it had
risen to 63 F but I did not run the solar heater since I thought it would be cloudy.  I still got a temperature rise though.

I guess i am so used to seeing our two demo systems running between 120-160 ppm nitrate and the tilapia love it....or have just adapted.  If we had the capacity to add another grow bed or two i'd like to see the level go down but i'm not incharge.

Ideally, you want the volume of the grow bed(s) to be 2X the volume of the fish tank, and you want them about 6 to 8 inches deep.  If you spread your grow bed media to that surface area, and plant it heavily, then nitrates will be absorbed well by the plants.  I don't do anything close to that.  I have a 550 gallon fish tank and less than half that volume of grow media, 250 gallons.  I should have 1000 gallons or more of grow bed media.  I don't even have the proper depth.  I have about 15" instead of 6 to 8".  

So I could definitely use a lot more grow beds.  I will look into this for next year.  I would have to find some suitable grow bed containers.  At the very least, I should spread out the 250 gallons of grow bed media I have to 6" depth.  This year, I'm going to concentrate on the solar heating.  I may move the solar heater to the side of the fish tank so I can grow something this year.

More later.


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Continued . . .

The above volumes are for a maximum stocking amount of fish which is generally regarded as 6 pounds for every 25 gallons of grow media.  You can go heavier if you have a particularly warm system such as those for Tilapia since the bacterial activity is heavily dependent on temperature.  The higher the temperature, the more activity you get.  It's also not linear but exponential.  For example, cutting the temperature by 10 F will cut bacterial activity by 50%.  So if you start at 100 units of bacterial activity, it drop to 50 units going from 70 to 60, and then to 25 units from 60 to 50.  That's a huge drop.  

The 6 pounds per 25 gallons of grow media is a maximum, not a starting point.  I remember conversing with someone in General Discussion about aquaponics and he stocked a phenomenal amount of fish in his system, and they all died, most likely due to an ammonia spike, nitrite spike, or both.  

You want to start with a low fish load, and as they grow and produce more ammonia waste, the bacterial population will grow as well.  While I will always have problems dealing with nitrates in my current system, it will be very difficult to run into problems with ammonia or nitrite.  There simply is too much expanded shale there and the bacterial load will wipe out any ammonia and nitrite quickly except under very unusual circumstances such as a hidden dead fish.  This is why it is paramount for me to have full visual access to my system.

The plan for now is to add the UV filter to kill any pathogens in the system.  I added the goldfish yesterday, but I'm reasonably certain they do not carry any pathogens.  My morning water temperature was 52 F and at noon it was 54 F.  I will also add 1 ppt (part per thousand) of salt as a prophylaxis against nitrite poisoning, though I am confident that is unlikely to happen.  If I can connect the UV filter and the water temperature increases a few more degrees, then I'll add a catfish.  If not, then I'll wait until tomorrow.

ETA:  Water temperature peaked at 58 F end of the day.


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Yes and this is where the boss and I disagree with our "grow bed" system.  As you have seen we have the 4'x8'x1.5" and the 150 gallon fish tank.  We trickle water very slowly at about 30 gallons an hour through this and you do not get the beneficial zones needed for conversion.  On top of that the surface stays moist and we are plagued with duck weed that robs us of the o2 and nutrients that our plants should get.  On the other hand the fish are happy and healthy, plants look good, and the water quality is where it needs to be.  

The beauty of aquaponics is you can set your system up however you want to.  I prefer to have a dry surface as it's better
to keep disease down.  However, that also depends on the type of plants you're growing.  Watercress loves a wet environment
so it wouldn't matter for them.  If the fish are thriving then you're right that it doesn't matter.

I didn't get much done today.  We had a birthday party for one of my son's and my oldest managed to go over the side of an
inflatable slide and completely fractured the right distal radius and ulna.  So I spent the day in the hospital and literally just got
in about 40 minutes ago.  He had to have anesthesia to set and cast the bones.

The temperature went from 56 F to 68 F today, so it would have been the perfect day to get a catfish in there.  I'm exhausted so
I'm not going to mess with it.  I did actually get the UV filter cleaned up and plugged it in.  Works great but only plugged it in long
enough to know if the light worked which it did as the unit has to be cooled by flowing water.  I also cut down the hose adapters
and, while it will be a tight fit, I think I can get the tube onto it with gentle heating with the propane tank to soften the hose as I slip
it over the hose adapter.

Maybe tomorrow?  Not sure as I'm going to work all day.  I'm still not sure what I will use as a platform for the UV filter.  Probably a
piece of untreated 2X4.

The good news is I took Friday off and I'm not working the long weekend so I'll have time to tie up all the loose ends hopefully.  If I can
get the UV filter up and running, I will definitely put a Channel catfish into the system.  My friend (yes, I only have one!) who does
a lot of aquarium stuff said he didn't think the goldfish harbored any ich so I may take the plunge and add a catfish tomorrow without
the UV filter in place.

Stand by for updates.

Brief update:

1) I finally got the UV filter hooked up and it looks like it is running well.  I tried putting a 2 X 4 over the fish tank as support, but there is some splash-back and the wood will rot in no time.  It's not treated but I wouldn't want it to be because it's toxic to fish, so today I zip-tied two 5 foot sections of 2" PVC pipe.  I then secured the UV filter to the PVC pipes.  I'll get some picture of the set-up.  The water runs into one side of the UV filter and travels in an outer tube and exits the other end.  Within that tube is a quarts glass tube that contains a UV fluorescent bulb.  As the water passes through, it is exposed to a 55W UV-rich light.  It looks pretty good and will hopefully kill pathogens.

2) I transferred one Channel catfish to the sump tank weighing 300 grams or about 0.66 pounds.  

3) My plan is to continue adding 2 or 3 fish a day until all 12 catfish are transferred.



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Hey man, i haven't finished all 18 pages yet, just found your thread. I started putting together an IBC system a couple of weeks back. got the siphon and tote cut apart this weekend. i have 2 IBC totes and haven't figured out im gonna set it up yet, 2 FT and 2 Growbeds or 1 FT and 1 sump and 2 Growbeds...Decisions.


i still need to add the airline to break my bell siphon. not sure i've got a large enough standpipe as it takes like 10 minutes to drain once siphon starts.. it's 1.0" but without the grow media in the bed my volume is much more water than will be truly in the bed.
http://www.ar15.com/forums/t_1_139/1751871_.html&page=1&anc=53870974#i53870974

anyway here's my progress in 2 weekends

Looks great!
I wish I had a source for totes I would add a set up like that. My bell siphon did better with a tube but I had to play with it.

I got super lucky with the totes. i was originally gonna build everything out of 35 gallon blue barrels, but someone in my 'hood works for a place that gets totes in weekly. he said i can have as many as i want for free.(wife likes the idea but doesn't want me to eat up the entire back yard lol)

This article goes over the stand pipe diameter depending on the size of the grow bed:

Automatic Bell Siphon

Once you have the media in there, you will have about 1/2 the amount of water, so it will drain in 5 minutes or so.  The rule of thumb is you should be able to run the total volume of your water through the grow bed media about once per hour.

If you don't have your heart set on one set-up versus another, I would go with 2 grow beds.  More filtration is good!  

1) Have you decided on the type of fish?  Tilapia?  I know you may start out with cheap fish to begin with.

2) Have you decided on grow bed media?

Texas.  That's awesome.  You'll have fewer water temperature problems.

ya mozambique tilapia(only species we are allowed without a license as they can't survive in water below about 70F, so risk of propagation in texas waters is minimal.

bed media....dilemma. i can get expanded shale but it's an hour away,  i can get pea gravel(did a vinegar test and it's good) bout 5 minutes away. no decision yet.

i am going to frame and fence in the whole system, so only the grow bed will be exposed to sunlight, i think i will also insulate with foam/radiant barrier. they will be next to the house so im hoping i will be able to keep the water temp above 70f over the winter(fingers crossed).

it should end up looking sorta like this

Unless the cost difference is big and you're trying to save money, I would go with the expanded shale, even if you have to drive a ways for it.  If you read through my thread, I ended up switching from gravel to expanded shale.  It's considerably lighter and therefore easier to work with from that standpoint.  It does have sharper edges, but once you have it in the grow bed, you're not going to really have to poke around in it much.  

From my experience and reading, I don't think there is any substantial difference in the ability to grow beneficial bacteria on either the expanded shale or the pea gravel.  So from that standpoint, either one should be fine.  I definitely like the cheaper price and local availability of pea gravel.

That's great about the Tilapia.  I think it's probably the absolute best fish to raise if you have the temperature requirements.  They seem to outshine all other fish in every other aspect.  Even breeding them is easier.  I would go with them in a heartbeat if I was able to but temperature is a no-go unless I were to do it indoors.

Are you going to have any light for them?  It seems awfully dark on a box.  I shouldn't talk because my Channel catfish were kept in my dark basement all winter.

We get a ton of sunlight here so having it exposed light will set off an extreme algae bloom. That said, it will be a trial and error think I expect.

I am trying to moderate the temperatures also. I live in the houston area where during the summer overnight temps rarely fall below 75 and afternoons can hit 95-100 for 3 months a year.

i am caught up to page 12 of the thread now and see your switch to expanded shale (the problem for me is i don't have a pickup, so getting the shale presents a problem).

I hear you about the algae.  I ended up splurging for a UV sterilizer.  While it kills algae, I got it more for killing any pathogens that may get into the system as well as bacterial blooms.  The best way to kill algae, though, is blocking out light as you are doing.  3 or 4 days and the algae is completely gone.



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I'll take some pictures this weekend but i have the bell siphon working, gonna work on the wood frame this weekend.

I also found the Expanded shale only about 30 minutes away, so my brother is gonna pick up a yard for me next week.

btw discovered delicious_bass only lives about 30 minutes away too. will be nice having a local resource i can turn too.

Anytime!   We are getting ready to move a little deeper into the country and I have listed my system for sale on a few other forums.  I plan on rebuilding whenever we get to the new place plus it would be difficult to maintain fish if I am back and forth between properties.  

You have my number if you need anything at all.

Edit- where did you get shale and iS it 1/4 or 1/2?

3/8" NATURE'S WAY RESOURCES. its just of i-45 and 1488