Save my Eel!! All other fish died!

[Cermet]

Just adding meds for the Pleco without knowing what is wrong is often more harmful than helpful. As everyone has said, large water changes and done often. Maybe raise the temp some, and add extra air. Until you have specific symptoms, little can be done.

[Joonkun]

i would move the pleco and tear the tank down, clean and recycle if it was me. especially if you arent sure what it is. plecos are slightly harder to treat then normal as they are scaleless i think. im not really sure im not a pleco keeper myself but certain small scale or scaless fish are more sensitive to some medicines. its really hard to tell when you can keep more fish. some bacteria can live for a decent while without a host to feed off of.

[lampreyzz]

The Pleco is pretty hardy fish. If it's not sick, then you might not need to do anymore medication.

Not sure the initial cause of the problem, but it sounds like the new filter maybe the cause. If the new filter is not clean thoroughly before using, it might still have some chemical residue on it. When switching to the new canister, I hope you have save some of your filter media as these media possess valuable micro to neutralize ammonia and nitrites. Otherwise you might just cycle your tank, that may explain why the die off. Fish stress, fish get sick, and created a heaven for fungus and bacterias. When there is a die off, it can cause whole brunch of side-problems because of nitrogen spike from die off.

As the previous poster suggest, now just tear down the aquarium, disinfect it, rinse the chemical off thoroughly, and rebuild it again. This time, do one fish at a time so the good bacteria can colonize your filter media. It has about 3-4weeks, or borrow a old filter media from a healthy tank to shorten the colonization.

In the meantime, have someone foster your pleco or buy a rubbermaid. Just keep changing water on your pleco until the new home is ready.

Put plants in tank helps improve water quality as the plants sucks up the nuritents. A healthy bacterial colony can consume additional oxygen. Ensure good surface action and run a secondary sponge filter as a spare bacterial colony if you need to quarantine fish in the future. This will help oxygenate your tank as well.

Good luck!

[lampreyzz]

here is an article about nitrification bacteria. there are other articles on the web, have a look.

http://watertreatment.enva.com/Produ...rification.pdf

beside borrowing filter media from another tank, you can spike your nitrifying bacteria with worm compost tea - they are loaded with nitrifying bacteria. other aquarist has success with shrimp from supermarket to accelerate colonization.