After adding a couple handfulls of Amazonia New to even out some slopes, I had a nitrite spike overnight a few weeks ago and lost 5 of the 6 orange zebra otos. I also lost some cherry shrimp, my turtle nerite and my amanos. Bummer =(
Week after that, rhizo began to take over my HC. Tried hydrogen peroxide dosing, Excel overdoses, limiting light. Nothing helped. Trimmed back the HC to the bone last week and added 5 regular otos and 3 more amano shrimp. Reduced photperiod to 5 hours. Algae problems are now completely gone. Slowly upping my photoperiod to 8 hours. At 7 hours now. HC is bouncing back from being trimmed down to almost nothing. Pulled some up in the process, but it is starting to carpet again.
Blyxa is growing like crazy. Will need to trim soon. Not sure how to go about trimming it properly.
Lessons learned -- Always pre-leach Amazonia when adding even a very small amount to a tank.