PlanetCatfish.com

I am wanting to know how often everyone cleans there tank and changes there water? A lot of websites say to do it once a week and a lady from a pet store told me that was way to often. She said to do it about once maybe twice a month at the most, because it would stress my fish out.

There are many factors to take into account such as filtration, stocking levels, amount of plants and other things. A good rule of thumb is 30-40 percent weekly to maintain optimal health in a well filtered not overstocked tank.

If your pet store is advising that water changes stress fish, I would find a new pet store. I actually took video this last weekend of some Pseudocrenilabrus spawning as I was refilling their tank.
-Shane

Depends on what you mean. I change water in (almost) all of my tanks at least once a week - but it really depends on the stocking level, and the type of fish, etc, etc. The more fish you have (higher stocking levels), the more often you would need to change the water. The more sensitive fish, more often (not only to avoid the water getting too dirty, but also to make less difference between the old and new water - the longer the water has been in the tank, the more "different" it will be compared to the tap-water you are replacing it with).

I never "tear down clean" a running tank unless it's absolutely unavoidable (serious problem with fish health or I have to move the tank to another location) - I have moved my three older tanks three times by now due to house-move, one of which was into a temporary house. Even when moving tanks, I try to avoid cleaning it too much.

Filters need to be cleaned (in tank-water, not tap-water) every so often. Internal filters sometimes as often as once a week, external (canister) filters I don't clean at all often - once every 3-6 months or so [I don't keep records of when I clean them, I just do it when flow gets bad or I feel it's time to do it anyways].

Obviously, if algae builds up on the glass, I rub it off - but bristlenoses make that task relatively low effort.

Shane's advice on finding a different LFS if the current one gives that bad advice is good (assuming we are talking about "take out some water and replace it with fresh water", rather than "spring cleaning" [which I don't recommend, but there are perhaps others that do]).

--
Mats

My tanks get about a 40% change every week, except for the bristlenose tank which needs 50% every 2 days due to the overcrowding in there. My tanks tend towards the heavily overstocked due to population explosions of bristlenose, cichlids, endlers and apple snails, so I really need to try and keep on top of nitrate levels.