They say every 6 months or a while, put your fish in a safe place, empty the tank water, wash everything inside it and then refill it (with dechlorinated water, of course). What about the nitrifying bacteria, then ?

MHN wrote:

this the first time i heard about it.... i never empty my tank for the whole
3 years and my fishes remains healthy. nevertheless, if you intend to do that,
just keep your filtering system running in an old tank water to preserve them...
then put it back to the newly refilled tank and you will be fine....

No, no, no! I never intended to do such a thing. I even had a little doubt. But now I'm sure that it ain't right. And another question: what's 'vaccuming'? (Is there some kinda vaccum machine for water ?)

MHN wrote:

there are some gadgets used to vacuum the gunks in the substrate...python
vacuum is the very common but some hobbyist used an empty plastic bottle,
bottom cut and attached the small end into the hose...by gravity of water,
you can vacuum the same gunk while doing water change...just replinish
whatever water had been discharge...

if you could remove all your subtract and wash it and then replace it, it would have a benefit to the tank and your nitrate levels. this is why some people have no subtract at all. its a cleaner way to care for your tank. the subtract contains a hell of a lot of crap you don't want even after you vac.

a vacuum used for water is a hose and plastic bottle fitted to the end. siphon pulls dirt and water out along with poo. you can get battery operated but they are crap. no power.

QUESTION: When you vacuum your subtrate (gravel), do you go ALL the way down to the bottom of it where all that black stuff comes out or just the surface? Have been told to do it too many different ways. Please let me know the proper and safest way. I am also switching tanks and did not know if it was safer to just leave that gravel and discard or transfer over to new tank. Thanks!

i do it all the way down removing even those tiny worms


but i got tired of doing it, thus i removed all my substrate

so what do you have for subtrate if you don't mind me asking. thanks!

nothing.... bare bottom tanks

I vacuum 2/3 of the gravel all the way to the bottom during my weekly 50% wc.
My beneficail bacteria are in my sump , i just care about clean gravel a lot.

that actually sounds good. i might do that and just paint the bottom outside of the tank black or paint some other design. i like that idea. thanks

I do a bit of both, i do top and bottom, depending on where I am getting most dirt. if its dirty deeper i stir and vac to remove it.