Yellow star polyp help

Supposely, this should be a easy coral for beginners, but for some reason, after I had it for 6 months, they are slowly reducing their number of polyps? Any ideas?

My water conditions are:
pH:8.2
s.g.: 1.021
Temp: 79
Ammonia, Nitrite: undectable
Nitrate: ~5 ppm
Phosphate: 0.25 mg/L

I have been adding the Kent Coral Accel after I noticed the reduce number of polyps, but it is still doing that. I had about 50+ polyps and now I'm down to may be 15???

By the way I also have a Green Brain, and it's doing great, it opens up everyday when the lights are on and catches stuff with it's tentacles at night. I have also closely monitor my Coral Beauty for hours and it has been it's best behavior and never pick on any of my corals...

 

I would suspect that your coral beauty may be nibbling on them. Either that or you're blasting them too much with water?

 

your salinity is pretty low

 

yes salinity and ph r low...ph should be 8.3...wat r ur supp levels? ie. iodine, ca, etc...

 

may yellows have slowly declined aswell. but my causes are notice obvious at this point