white cloudy snotlike substance

Question
Hi there, I woke up the other day to a very big problem. My tanks rocks were covered in this whiteish clear snotlike stuff all over them, and most of my fish were dead. i quickly removed all the living fish and put them into a bowl of fresh water and a bubbler and completely emptied the tank. I wiped the whole thing down with hydrogen peroxide, replaced all the rocks and put all the ordiments are in bleach, they are still there as we speak. i refilled the tank and everything was ok for about two days when i started seeing the substance again but this time its on the walls and not the rocks. Would you know what it could be and how i can get rid of it. i figured and was told it looked like a fungus but if that was the case wouldn't have hydrogen peroxide have killed it?? I also have researched information saying that the white stuff could be from over feeding. But they have only been feed twice in this tank and very little both times. please help i have already lost most of my fish i don't want to lose anymore of them thanks for you time!! ^^

Answer
Hi Miranda,

If the substance was slimy, and had a bit of a smell to it, it may be a type of bacterial growth. It's VERY surprising that the peroxide did not kill it. Are you sure that you rinsed out everything? Bacteria can multiply even if there's a single particle of it. Try treating the tank with Maracyn. It's a product available at where you buy fish. Maracyn is an anti-bacterial medication for fish, and it should take care of this slimy stuff too. If you cannot find Maracyn, another anti-bacterial fish medication will work. If it does not work, after 7 days, then I would recommend that you strip everything down once more, and soak everything in hot water for 5 minutes. NEVER use ANY chemicals to treat the tank, unless it was designed for aquarium use.

Once you get rid of it, performing 20% water changes twice a week along with a gravel vacuuming will prevent any future growths. The strange white stuff may be coming from the environment outside the aquarium - make sure nobody has dumped anything into the aquarium, or that nobody has recently sprayed chemicals in the area, etc.

It does NOT seem like a problem due to overfeeding. Don't worry, it's probably not your fault at all. If you have any other questions, feel free to ask me again!

Good luck, and Happy Fishkeeping!