Tap Water With High Nitrate Content

[mark dean]

Just tested my tap water for NitrAte,found it contains around 50ppm.

My question is when the time comes to do water changes,which i gather is to reduce nitrAte.I will be changing water of between 50/110pm with water that is allready 50ppm.

Any suggestions,as bottled water would work out expensive doing a 15% change every week.

Any other methods or ideas.

tank cycling at present. 120 litre

Thanks