Bio crash?

[prissy]

Changed too much gravel. vacumed too much. Changed sponge too soon.50 gal set up since sept. with large gravel.Got rid of 50%gravel,cleaned too much, water like pea soup.I think I wiped out my good bacteria.I am changing 25% of water a day now.Lost two corries ,didnt have trouble till I disrupted everything.Anything else I can do?Thank you Prissy

[kveeti]

You disrupted something, but I'm not sure if it's your bio filter... Did you actually test for ammonia and nitrite? That would be my first step. Then you would know exactly how much water changes to do to bring those down again. The only reason I say this is that when I read "pea soup" I think green water (?). That would mean algae and therefore the water has less oxygen. I'm not sure but I don't think water changes alone will help that problem. There are a number of threads on green water and solutions that you can search for (search "pea soup" - I got 12 hits).

[prissy]

Forgot to mention also scrubbed all fake plant,no real ones.
just checked all water tests ther,e ok. No alge showing.Appreciate all the help I can get, Prissy.

[Prometheus]

Vacumming the gravel shouldn't have caused you to lose much (if any significant ammount) of your good bacteria...

My thoughts are: When you changed the gravel, you disturbed some sediment that was trapping in some nitrites or nitrates (maybe ammonia) from deep at the bottom of your tank (would explain that pea soup cloud from the bottom), and thats what killed your fish... Since everything is back to normal, your bio thats in place took care of it (as quickly as it could) and thats why your water levels look fine now...

I know the first time I knew I was susposed to vacumm my gravel (about 8-10 months into the hobby) I was vacumming up a dark green sludge! yuck:eek:

[Gunnie]

I recently had a similar experience, but the water was milky white. I came home from work, and when I turned my light on the tank, it looked like mass murder. My parameters appeared normal, and after many possible reasons for the deaths, the most logical one for me was that a gas pocket in the gravel had been opened, and the stuff in the pocket poisoned my fish. I have parts of my tank with rocks that don't get throughly cleaned every week like the rest of my gravel, and these areas apparently get a build up of bad stuff that turns into poison if it's not properly aerated on a regular basis. I wondered how people with heavily planted tanks avoid this since they usually don't deep vacuum the gravel, and it was suggested to poke the planted areas with a knitting needle at least once a week to keep it properly aerated.

[RTR]

Heavily planted tanks do not need the substrate stirred, as plant roots transport O2 to the substrate. It will be anaerobic at depth, but not profoundly anoxic to the levels where H2S or methane are generated.

Highly organic old substrates can reach those dangerous levels though.