I have a 30g heavily planted tank housing just crystal red shrimp. Last night everyone was active and fine, this morning I found half my adults and all my juvies deceased. No clue what happened. Water tests out at: ammo 0, trite 0, trate 5ish, ph 7.2 temp 72. Sigh, what a set back! I had just gotten my stock numbers up to about 40 adults and was about ready to offer them up to share