I'm wondering how often I should make a complete water change? I.e., remove fish from aquarium, take gravel and plants out, etc. I used to do a complete water change EVERY other month. Ridiculous, I know, but I don't that anymore. I've heard that you should strip down your aquarium twice a year. Is this true? Thanks.

I don't think I've ever heard of this being a good idea unless you have an incredibly vicious disease outbreak. The first two months of a fish tank are the most difficult and dangerous, and doing something like this simply keeps you in that phase of the game permanently.

That sounds like a lot of unnecessary work. And I agree with Kanus that you risk uncycling the tank. Here's a graph of bacteria growth over the first 40 days: http://www.theaquari...cling_graph.png

Perhaps you might be interested in Diana Walstad's book, Ecology of the Planted Aquarium. In it she describes a tank setup that gets two water changes a year and has healthy fish. I personally do a water change once a month despite my nitrate never accumulating above 20 ppm, because I find the plants are not nice to one another and I have lost species to alleopathic warfare when I skimp on water changes. But if you go with non-alleopathic species or only a few species, yeah, I agree that the twice a year water change can be totally healthy in a heavily planted tank. I have a Walstad saltwater tank that never, ever has gotten a water change. Here's a few videos of it a year and a year and a half after setup:
http://www.youtube.com/watch?v=CzX1Py3VODshttp://www.youtube.com/watch?v=ppOte9qOb9M
There's only a single species of 'plant' (our native caulerpa prolifera) so I don't have to worry about alleopathic warfare.

If you have a non planted tank, I recommend measuring nitrate every week and doing water changes to keep it below 30 ppm. Ammonia and nitrite should never be above 0 ppm. Use dechlorinated temperature matched water to do the water change. If nitrate cannot be reduced to 30 ppm with a 1/3 water change, wait a day and do another 1/3 change. If your tap water is different than your tank water, a larger water change can stress your fish (pH, hardness, salinity, temperature differences). If your tap water's the same you could theoretically do a 100% change but it's rare to find everything exactly 100% the same. My tap water has 0 DH and so does my tank, but the pH in the tank is around 6 and the pH in the tap water's around 7.

Also keep in mind that things other than nitrate can accumulate. The substrate in my 55 gallon tank unfortunately has mulch in it (this pains me greatly) and if I don't do a huge water change on a monthly basis or spend money on activated carbon, it turns yellow. Lame. And I know of some people who have problems with excess phosphate.

I would personally never strip down and clean a tank, unless of disease. Otherwise regular small water changes are all that is needed. Filters, make sure you clean them to the extent that they flow freely, and no more. No cleaners, and no chlorinated water.

Ditto what Matt said, with the caveat he noted. When you are medicating a tank, you should drain the water daily. As John Gratzek said once, drain it until the fish wonder "Where the hell did all the water go?"

In the old days of UGF's, we used to break down tanks every couple of years. Then came this thing called a Python. I haven't broken down a tank in MANY years, other than when I had to move it.

P.s.: For either deep sand bed or Walstad tanks (or whatever you choose to call them), a Python is right out.

P.s.: For either deep sand bed or Walstad tanks (or whatever you choose to call them), a Python is right out.

I use a Python no spill clean n fill in my Walstad setup, the freshwater ones with multiple plant species that get a water change once a month.

They're still really handy. You can get the mulm off the surface of the substrate with it if you want to, you just don't need to dig around the way you would in gravel.

Erica, you just need to get used to yellow water. It looks good, and the fish love it, once you get used to the idea.