Who Gives A Fish Forums

Nitrate tolerance depends on age. Juveniles need under 20 ppm for proper development. Adults can handle 30–40 ppm if other params are pristine. Test your tap—sometimes the source is the culprit. My tap's at 10 ppm, so I'm fighting an uphill battle with water changes alone.

Re: General Questions: Cross Contamination

I learned the hard way that it's better to be safe than sorry. Resist the temptation to cut corners when you're new to this. I recently lost 4 out of 5 discus I got from a supplier I'd used before. What led to the problems I saw isn't entirely clear, but ...