5 gallon cylinder pico

[mxpro32]

for some reason my zoas aren't flattening and opening up.  I'm wondering if the a160 isn't enough light.  my parameters are:

 

salinity  1026

KH  9.3

CA 430

nitrates  5

phosphates .03

mag  1400

 

I'm wondering if my phos is too low.  my coralline is sucking it up so i have to add it all the time.