Phosphate reactor and Mandarin Dragonette

[joegoersch]

I bought a red mandarin dragonette a couple of months ago for my 120 gallon DT with lots of live rock in the tank and in the 40 gallon sump/refugium. The mandarin is not yet taking prepared foods that I feed the other fish (flakes, Mysis, brine or nutramar ova), but seems to be fat, successfully hunting copepods or whatever else it’s picking from the rocks.
The problem I am having is algae, particularly hair algae on the rocks and rapid accumulation of algae on the aquarium glass. I’m using DI with zero TDS, so I suspect I’m having a problem with phosphates. Nitrates are about 5. I suspect I am overfeeding but am afraid if I feed less, the other fish will out-compete the dragonette for the copepods.

I’m thinking about getting a phosphate reactor for my system and have a few questions.

1) How soon before I can expect to see an improvement in the algae growth once I start up the reactor ?
2) Will this diminish the food supply for the dragonette ?
3) Any recommendations for a good phosphate reactor for my system ? Any other suggestions ?
Thanks.

[Sk8r]

Your fear is justified.

Limit use of same. If you have hair algae, you have way too much phosphate. But if you don't have some film algae, you may have too little to sustain your copepod population. Combtooth blennies and other algae-dependent fishes may suffer.