Corals shrinking

Question
I have a 125 gallon saltwater aqaurium and I have a few filter feeding corals one is a colt coral  anyhow they been shrinking the last two weeks not looking good at all I've tested salinty and ph and temp,nitrite and nitrates . Nitrates r high but always have been a little high . I use prime witch is supposed to detoxifie nitrates . Tanks been going for about eight years everything's  always been fine until recently the only thing that's new is I bought this product called reef roids for filter feeding corals  and installed new hoses on my pump with two new shut offs that I think are brass. My fish are all nice and healthy what do you think is making them shrivel up

Answer
I'd recommend to check your phosphate level. When it's too high it tends to bother filter feeders.

There's several great products on the market for phosphate reduction / removal, including ATM's Agent Green Phosphate Remover and Seachem's SeaGel.

Regards,
David