Advice needed please

[merangue]

We have a 170L tropical tank. The test strips are showing: NO3 - too high; GH - too high; PH - slightly low, the remainder are fine. The fish appear to be okay but we want to add more fish. Any suggestions what to treat the tank with?

 

[Dallascowboys16]

We have a 170L tropical tank. The test strips are showing: NO3 - too high; GH - too high; PH - slightly low, the remainder are fine. The fish appear to be okay but we want to add more fish. Any suggestions what to treat the tank with?

Don't treat the tank with anything. With PH stability is far more important than a. value. She goes for GH. As far as the NO3 goes though anywhere between 0-20 is considered appropriate for most tanks and the only things that will lower its levels are consumption by plants and/or algae or water changes. How old is your tank and is it cycled?