1 year old 75 reef tank failure to thrive.

it could well be your lights are "burning" your corals, how high are they above your tank?

gfo will most certain strip po4 from the system (sps worst enemy at high concentrations) I would still double check your result with someone in the hobby you trust...

hopefully others will share their thoughts on the matter as well

 

I would test your Mg levels - may help explain the coralline algae. Based on your ALK and CA, its probably not bad - but worth looking into. Your temp is a little high - 80 - not terrible but a little high. Is that temp consistent all day, or does it fluctuate? Are you running and regularly changing activated carbon in the system. Soft corals tend to be dirty - and many are active in Chemical warfare. I have a bunch of softies in my tank - I like the way they look - and I'll tell you when I started running carbon it really changed the game for me. Finally - what kind of SPS are you trying? I'd start with something easy - like an ORA SPS and see how that goes

 

I would test your Mg levels - may help explain the coralline algae. Based on your ALK and CA, its probably not bad - but worth looking into. Your temp is a little high - 80 - not terrible but a little high. Is that temp consistent all day, or does it fluctuate? Are you running and regularly changing activated carbon in the system. Soft corals tend to be dirty - and many are active in Chemical warfare. I have a bunch of softies in my tank - I like the way they look - and I'll tell you when I started running carbon it really changed the game for me. Finally - what kind of SPS are you trying? I'd start with something easy - like an ORA SPS and see how that goes