How long do I have to wait to do another water change?

[Rememberme]

I did a 25% water change yesterday and I wanna clean my sand a bit more because it's still looking quite dirty. How long should I wait until I can do another water change, as to not kill off too much of my beneficial bacteria?

[CronicReefer]

Feel free to do another one today if you like. The bacteria is mostly contained on and in your live rock and your filter media if you have any extra type of biological filtration setup.

[jservedio]

You can do as many water changes of any size as often as you like as long as you take some precautions to avoid parameter swings. As long as you match the temperature, salinity, and alkalinity of the WC water to your tank, you can do 100% water changes daily if you really wanted to.

 

When I have problems with my 2g pico, I typically do 50%+ water changes daily or ever other day until I remedy the problem. This is why it is very important to use salt that matches your tank's water parameters as closely as possible!