Coral won't grow!

[Myka]

Originally Posted by Metrontech

Phosphate - .25
Nitrate - 0
Kh - 89.5 (5)
Calcium - 640
Amonia - 0

Are these optimal?

No. I don't trust these readings to be correct though. If you're not adding anything with calcium in it, then the readings don't make sense. Unless you have one of those old buckets of Kent salt laying around that had calcium that high! I digress, which brand of salt are you using?

Leaving the word "optimal" out, softies are quite happy within these ranges:

Calcium 370-450 ppm
Alkalinity 7-10 dKH (125-160 ppm)
Nitrate preferably under 20 ppm, but many tolerate up to 100 ppm
Phosphate under 0.25 ppm, preferably under 0.1 ppm

Neither fish nor your basic softies (leathers, green star polyps, Ricordea, basic mushrooms) care much about nitrate. Of course, both fish and soft corals will grow faster, have better color, and generally be healthier if you keep nitrate much lower.

Phosphate doesn't affect fish much either, but will affect corals (of all types) much more. Softies are tolerant, but as with nitrate, they will do better with low phosphate.

Originally Posted by Metrontech

Is there any way way to get rid of the phosphate?

Or just water changes?

Water changes are not an efficient way to deal with phosphate. First, get an accurate reading. GFO (granular ferric oxide) will lower phosphate, but it can be very aggressive. If you use too much on a tank with high phosphate (0.25 ppm is high) you can lose corals.

Go get an accurate reading for phosphate and nitrate first from you LFS, then come back and post it. You could test calcium, alkalinity, and magnesium while you're at it if you want. We can recommend what to do next once we know accurate readings.