I’m confused on how I have 0 nitrates with Red Sea marine Nitrate test kit but am getting a couple patches of gha in my sand bed. Tank is 125 gallon mixed reef with a 30 gallon sump. 2yrs old. I have several different macros in my refugium and run a reactor with phosguard. I no I’m probably getting a false reading on my test but question is how do I get around that? In other words.... how do I no if I really have 0 nitrates or a false reading?




