Hey everyone for some reason I can’t figure out how to get my nitrates down. It feels like I have tried everything. I did a 50% water change yesterday and it seems as though my nitrates barely went down. What’s even worse is my phosphate is stuck at 0, so my macroalgae won’t grow. It’s as if the macroalgae needs both phosphate and nitrate to grow, but I’m only limited to nitrate. I also have a bunch of cyanobacteria that keeps coming back on the rock work and I don’t know what to do. I’ve been stuck with this problem for quite some time now. Ive got at least 80 pounds of live rock in my tank as well. I have a 55 gallon tank.

My Params:
Ammonia- 0
Nitrite- 0
Nitrate- 40ppm
Calcium- 460ppm
Alkalinity- 11dKH
Phosphate-0
Magnesium- 1350
Ph-8.4
Temperature- 79.2 F

Livestock
Two ocellaris clownfish
One yellow watchman goby
One bartlet anthias
5 blue leg hermits
5 red leg hermits
3 trochus snails
3 nassarius snails


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