Butters

Hey, I'm wondering how big of a water change I should do after the nitrogen cycle gets done in my 20 gallon. I noticed that the tank is slightly tilted to the front and I would like to try and fix that, thats why I want to know if maybe I could just change 100% of the water. thanks!

Lucy

I wouldn't do a 100% change, could you shift it doing a 50 or 75%?

Butters

I might be able to, I wouldnt have to move it that much, just to get a something little under it to prop it up or something. thanks!

clinton1621

Also, just as a precaution... level the stand, not the tank itself... some people try to level the tank by sticking things under it, this will eventually crack the tank because of uneven pressure... if you level the stand then the tank will also be level =)

Lucy

Good point, Clinton.

nitz

I think the size of your water change depends on your nitrate level. If you have a really high nitrate level, I've heard people suggest a 90% water change. I don't think you're harming the bacteria by doing this as they'll be getting the needed ammonia when you add fish or keep adding ammonia until you put fish in. I did a 50% water change when I cycled my tank fishless but my nitrate reading was about 20ppm.

clinton1621

If you have a large container you could take out all the water, but save some in the container to put back in... like nitz said changing it all wont necessarily hurt the bacteria BUT it will put you into a mini cycle for a few days

Butters

thanks guys, I was planning on leveling the stand and not just the tank FYI. I was also thinking about doing what you said clinton. thanks!