tank cleaning

mpalffy · Post by **mpalffy** » 19 Apr 2003, 19:19

My 50 gallon tank has coarse plastic coated gravel on the bottom; it has been occupied by my 7" yellow bullhead for about a month. I stirred the gravel a bit recently, and was amazed by the amount of sediment that got stirred up. I assume this is waste from the catfish...... Can anyone advise me on cleaning the tank - or is it safe to let this sediment/waste build up indefinitely? (still waiting for instruction book on tank maintenance.)

thanks - peter

DeLBoD · Post by **DeLBoD** » 19 Apr 2003, 19:33

Don?t stir it up, use a siphon to gentle lift out the sediment(waste) from the gravel ,there are a load of undesirable toxins in that lot.
Some one will be more informative, just don?t stir it up any more.

S. Allen · Post by **S. Allen** » 20 Apr 2003, 07:12

eh, I'll not be too much more helpful here, but... removal with a gravel vacuum attatched to a siphon hose when you do water changes will do wonders. If you notice that it's not going away as quickly as you like, do another water change a few days later, but don't drain the whole tank anytime(in theory this would be fine, and in emergencies I've done it, but not without a lot of worry.)

Basic problems with stirring it up are, well, most obviously, it's gonna look nasty. More important from the fishes point of view is that the waste that was in the gravel was decaying somewhat slowly, and slowly leaking the nitrogenous compounds into the water... this is normal in any fish tank, it's why we've got the cycle worked out... the bacteria that remove the compounds are pretty well set on the normal decomposition rate... if you stir it up it tends to decay a bit faster and can overload your biological filtration. If that wasn't bad enough, in really severe cases, and most likely not yours, the decay reaches a state that's been undisturbed so long that the bacteria inside are using compounds to make their necessary supplies, existing in a state where very little oxygen penetrates. This is not, in itself dangerous, and actually the same ideas are used by people out there who know what they're doing way better than I do to reduce nitrates, as the bacteria derive their oxygen by breaking up nitrate and releasing a substance that gasses out harmlessly. having flunked chemistry and not getting great grades in the microbiology area either, I'm taking they're word for it. Woo, got way off course. anyhow, if the pocket(most likely to be found in places tough to access, like under decorations and stuff) is disturbed it apparently throws off a rotten egg smelling gush which contains a chemical that can kill your fish...

geez, my memory's all screwy, hopefully that all came out right. Somebody please correct me if I'm wrong.

Lastly, there are expensive gravel vacuums, some battery operated and all sorts of stuff, I'd suggest staying away from these. main reason is that if the gravel's dirty it takes very little extra effort to just do a water change with the gravel vacuuming. only times the others seem to be a good idea is in stingray and other large-poo fish tanks with sand or a bare bottom, as it's a simple little second and you've got a big BM that's no longer rolling around on the sand...