I texted my dad the fish expert and he replied, "Put Ich-Out or Rid Ich in the tank and keep the light off until the treatments are over. Stress causes fish to be susceptible to Ich." And then he said that my mom said "fry the rest in butter", but don't tell your son that... heh.

You can get Rid Ich at Petsmart for sure, and I'm certain you can find either one at most pet stores and of course online. Good luck!!

If your son wants to replace the fish he lost,I'd buy a smaller tank for quarantine.Alot of place like wally world,pet smart,ect ect,the fish aren't in the greatest shape.You shouldn't have probs using a 5gal. tank.





Back when I had a few tanks,even when I bought from a reputable shop,I still put them in the quarantine tank for about a week or so.I just used a 10 gal. and/or 30 gal.*pending on the size of the fish/how many* no lights,small heater,and a small power head to circulate the water,add chemicals for ich and such.Week later,dumped them in the bigger tank/s.





One  diseased fish can wreak havoc in a tank...as I found out the hard way
 

I've fought ick before.



I suggest just starting over. It's just not worth the hassle and in the end they're probably all going to die.



Balas can very ick prone.

20 gallon tank?   Is this a well established tank that you've had for awhile or a new tank?

First impression is that you are way over stocked for the tank.   I never really bought into the 1 inch per gallon rule or whatever it is but it seems to be a pretty decent rule to go by when mixing species.   But I wouldn't even consider that a 20 gallon tank would support 20 individual one inch fish.   I'd divide by 1/2 and wind up at maybe 10 one inch fish for 20 gallons.   Fish get stressed and become highly susceptible to infections to the point you've got to have immaculate water to be able keep high population densities.

Also, if you just set the tank up it's gotta cycle.   Look up the ammonia and nitrogen cycle to get an understanding of how the tanks get set up.   It's the reason you always go with cheap fish from the get go on a new tank or after moving a tank.    Risk of loss is very high during on set.    I've got a 30 gallon tank in the house I set up about 2-3 months ago that I still have yet to put fish in because I'm waiting on having the plants established and the cycle complete before adding a couple fish.

My main tank is a 55 gallon tank with only two Jack Dempseys.   They are about max size for the tank and couldn't be happier with the conditions even though my water quality is virtually shit.   I've got plants in handling a bit of biological filtration along with two biowheel filters rated for 70 gallons each by themselves.   But I only do water changes maybe once every 6-9 months which is pretty remarkable and goes against most of the common advise.   I've had the two Dempseys for about 2 to 2 1/2 years now with such conditions.

For comparison....

Same tank, with only 8 stupid little colorful guppies was a PAIN IN THE ASS to try to keep running.    I did have luck with 4 Bala Sharks in my 55gallon tank but they were smallish at maybe 3-4 inches long.   Balas don't seem to take stress very easily, in other words they spook the fuck out and run headlong into a side of the tank(repeatedly).  I would not put balas in a tank smaller than 55 gallons for the reason that they are spastic.   A comparable 20 gallons at a pet store is fine because they probably lose 1/2 the fish a week and just keep restocking it and you never get to see the loss.

Most incredible thing though...

Stupid Dempseys.   I was going to try to put a few Bala sharks back in my tank, got two mediums that were about as big/long as my pinky finger.   Came home from work to see the larger Dempsey with only the remains of a tail fin sticking out his mouth.   Yep, he ate one and he wasn't spitting it back out either due to the fact that Bala's grow a spine off their dorsal fin.    I never lost that Dempsey, he just digested that Bala and kept on keepin on.    Very impressive given the fact that the stupid Bala shark that it ate was a good 1/2 the length of the Jack Dempsey that consumed the Bala.    At some point I am sure my Dempsey was pooping out the head of the Bala just as he was getting to digest the tail.    

My recommendation?   Keep the tank to maybe 3-4 smallish fish like mollies(hate those fish) or Gourami.   Or maybe get one decent Cichlid.

Also, if you have room you could go bigger.   Bigger tanks are more forgiving while smaller tanks are generally the PITA because they are so sensitive to small changes.

Once you get the outbreak taken care of you might get the temperatures down on the tank to the minimum listed for the breed of fish.   Slows the metabolism, slows their digestion, keeps the waste from fermenting quite so quickly, and seems easier to care for them.

Any honest to god actual plants?   Or just plastic decorations?


To me, a 3-4 month old tank is still new.   Early on, I'd say that any progress made on cycling the tank is a fragile state.   One or two cheap fish just to ensure it's started and then watch them for stressing/dying off to signal tank progress.    You may just begin to get the cycle going early on with only one or two fish and it may be able to cope.   But add too many fish too quickly and you can throw the cycle out of whack again.   Too many times I've heard the term/phrase "toxic soup" when referring to the conditions of an early tank.

If you don't have a PH, Ammonia, and Nitrate test kit then you need to get one.    It will help tell you where you are in the cycle as well as indicate whether you have too many fish.

What kind of filtration do you have on it?    I'm a pretty big fan of biowheels because the wheels keep the beneficial bacteria while allowing you to still change the filters without throwing out all your beneficial bacteria.   The only problem is they can be kinda noisy with the running water.

I'd do a partial water change.   Put in some real plants if you don't have them already.   Watch the one remaining fish.   Then as the plants take root, slowly try to get it up to maybe 5 fish like Guppies or Mollies.

I got my Mollies going pretty well in my 30 gallon tank when I had them.   To the point that they started breeding and generally pissing me off because they eat and breed so damned much.


I think of my 55 gallon tank less as an aquarium and more of a pond.   I'm trying to focus primarily on good plants, with the sediment from the fish providing nutrients to the plants.   It doesn't allow me to have as many fish but what I do have is so easy to take care of that all I've done for months is add food and water.

I get an algae break out maybe once every 2-3 months but it's controllable and a good cleaning of the glass/rocks tends to keep it at bay again for another 2-3 months.


My next interesting foray is going to be my 1200+ gallon pond with the 3 smaller satellite ponds(two 50s and one 150+).   As spring takes off into summer I'm going to have cichlids in the main pond and community fish in the smaller ponds.

If you are still trying to fight off the ich I would raise the temp to 86* and leave it there for 14 days.  Raise it a degree or two every few hours.  Do you have a water test kit?  If you do post up the results.

Ok, I see you have an ich case, but also balas will eat/kill your tetras and other balas unless they are usually kept in school sof 2 or more. Having said that if ich is the main cause for fish loss raise the temp or try topical solutions found at any pet store. I can't remember the name of the stuff I used, but it came in a bottle the same size as a bottle of craft paint and...nevermind it was called ick away. add the prescribed amount and do a 50% water change after each dose. That cleared it up right away.

A quarantine tank is by far the best investment I've done for the hobby. All new fish and plants go through two weeks in my QT while being treated with copper. I also keep the tank water level below the HOB filter so the splashing water aerates (also the fish goes nuts playing in the bubbles too). You don't have to worry about cycling the tank, just do daily water changes to keep up with the waste levels. Since QT is considerably smaller than your main tank, it's less work and cost per water change and adding back in any salt/chems. I also have separate sets of water buckets and nets for each tank so I don't cross contaminate.