Join Date: May 2008
Location: San Francisco, CA
It is safe and I have done it where my nitrates level were 40ppm+. Is it recommended for shrimp breeding tanks? Definitely not. But if your primary goal is keeping your plants well-fed, then it's fine. They will live through it.
I have kept cherries with these high levels. I believe Tom Barr has kept a breeding population of crystals with those levels too.
Again, if your goal is to keep a breeding colony of shrimp, then keeping nitrates level as low as possible is your best bet. <10 would be ideal.
If you just keep shrimp for ornamental purposes and don't really care about breeding and such, then dose away.