Are all macroalgae equal

[Subsea]

Also, some macroalgae wage allelopathic war with corals that inhibit their growth: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3203809/

We have known about chemical warfare between corals for years. On a reef in the wild, an experiment in macro chemical warfare was conducted with a meadow of macro in the vicinity of grazing herbivores. A hard coral was brought into the near proximity of macro with observed detriment to coral within days. The real surprise was a dramatic increase in grazing by herbivores only on macros in vicinity of coral. The hypothesis from this is that macro can change internal chemistry to produce differrent chemicals for different purposes. Once coral warfare became the priority, the macro no longer produced noxious chemicals to ward off grazing.
Just some random thoughts.

 

[Jl330]

Nitrate is one form of nitrogen. Ammonia & nitrite are the two other parts to total nitrogen. Certain macros & certain corals prefer ammonia to nitrate.

PS. Many dose potassium nitrate. With my large systems, I dose ammonia for economy.

My nitrate is running over 25. I don't think that's the problem