Why, exactly?
Just the worry about phosphate dropping?
Sorry I actually posted that a while ago I don't know why it just showed up, been having internet issues for a day or two from a snowstorm so maybe that's why. At the time I didn't realize the OP was battling dinos, dosing nutrients is a great way to battle them, but i would try reducing the refugium photoperiod first since that's already incorporated into the system and the less you have to dose the better imo. If that doesn't work then dose away.
My comment about not dosing nitrate until the fish population was maxed out assumed the OP was trying to improve coral coloration or growth, not fighting dino. I believe that for several reasons:
1. You likely won't need to with more fish (likely, not always true)
2. I know people who have basically crashed their tanks from accidentally bottoming out phosphates very quickly by dosing too much.
3. I believe fish waste is a better coral food
4. I don't like dosing more than I have to, and fish are just there, much easier.
That's just my opinion, dosing nitrate works great for tons of people, I just think its more risky/complicated than just adding fish.