this tank is about a year old I use aquaforest pro biotic reef salt a little carbon and a big skimmer I feed everday have a pair of clown a yellow tang and a royal gramma in a 90 gallon. my phosphates are reading 1ppb wich is to low and most my lps suffer in the color range most start to fade even with regualar feedings of reef roids reef chilly and fauna marine lps.. what can I do to get my phosphates up and keep them around 3 or 5 whichever is better for lps.. its an lps tank only I do a 5 gallon water change a week and filter sock change