Ammonia spike while on vacation, what to do now?

[fishy_sarah]

I returned from vacation tonight to find four dead fish in various stages of decay in my 29 gallon tank and one fish dying. All of the dead fish and the dying one were platys The rest of my fish, the 4 neons, 5 tetras, the three remaining platys (one adult and two fry) 2 molly fry, and 4 barbs, looked awful.

I immediately tested nitrites and ammonia- nitrites were fine but ammonia was through the roof. I did a pwc the day I left and readings were fine then. I think what happened was one fish died, and was left to rot in the tank, and it caused a chain reaction- as the ammonia levels rose, more fish died leading to a further rise in ammonia, etc. I was gone a week so there was plenty of time for this disaster to happen. BTW, my tank runs a Whisper 30, temperature at a constant 78 and has been set up for one year.

Well, I did my 80% water change, I have the dying fish isolated in clean water but I'm sure its too late, he is really bad off.

My question is, is there anything more I can do to help my remaining fish recover? Like add aquarium salt? I am keeping the water as clean as possible.

[Chrona]

After doing the large water change, you should be fine. Your original bacteria colony is still there (and probably a bit larger than normal) so it can easily keep up with the decreased bioload. As long as you have no nitrites, don't add salt to the main tank. The only fish you have that can benefit from salt normally are the mollies, and it's not worth adding it because neons are rather sensitive to the stuff apparently. Salt is only helpful against nitrite poisoning and external or free floating parasites and in some cases, helping dying or very unhealthy fish regulate their osmosis. If you have the platy isolated, then it will benefit from 1 tablespoon per 10 gallons of water (you will need to scale down depending on your holding tank size) Make sure to dissolve it first, then add it slowly.

For the rest of your fish, you can try adding some Melafix to prevent any bacterial infections as a result of the weakened state. Also make sure to watch for any signs of ich (will look like the fish has been covered in salt or something)

[Lady Hobbs]

You were worried about taking this vacation and guess you had call to be. Nothing you can do about it now but do as chrona mentioned in the above post and start over with new fish. I would keep the ill one isolated as he's liable to get ick or fin rot now or both. He's been pretty stressed out. One tough guy, he is.

[kimmers318]

Alot of the time some simple clean water (which you have already headed towards) and some stresscoat will do wonders.
It sucks that this happened while you were on vacation, but there isn't much you can do about the losses, just try to bring the healthy fish back to optimal health.

[Nautilus291]

I would watch out maybe a disease started this whole thing in the first place. Watch your other fish to make sure they arnt showing any signs of disease.