Water Change Explanation

[ishar]

I know this seems like a really simple task, but I was wondering if someone could give me a run down on water changes. My situation is a 20GH planted tank with 6 fish and a shrimp, with fertilizers and water conditioner dosed at recommended doses. It is freshwater and I have a regular aquarium gravel in the bottom (to be honest, I think I have too much down there). The tank is, as far as I know, cycled fully.

Currently I am using a gravel vacuum, and do either a 25% or a 50% water change sucking up debris form the gravel all the while. In the beginning I did 25% and every third week I did a 50%, but the last two or three weeks I have just gone ahead and done a 50% water change.

Is this too big of a water change too often, or an I ok to be doing this? I have fry in there at random intervals and try to keep it as clean as possible to give them a better chance at survival. I was just wondering if this would stress out the cycling bacteria too much or is this fine to do?

 

[Dino]

As long as you are messing with only about half of the substrate at a time, you should not be bothering the bacteria.

I do 50% changes here on a weekly basis.

 

[FroggyFox]

Water changes are not going to hurt your bacteria as long as you take care to not let chlorinated or really hot or really cold water touch your filter. (ie, turn your filter off while doing water changes) If your tank wasn't cycled you would want to be watching to do additional water changes when your ammonia or nitrites got too high.

It sounds to me like you're doing well. A 50% change once a week is not too much, esp if you feel like it is enough. You need to try and make sure not to stress the fish out so things like making sure the temperature and chemistry of the water you're putting back into the tank isn't much different than the water in the tank.

Edit: Depending on the type of filter you have, messing with part or all of the substrate shouldn't matter. If you have an undergravel filter then you need to be more cautious since you are vaccuuming your filter every week, but I wouldn't worry about it otherwise.