low nitrates, high phosphates, low nuisance algae

[JoJosReef]

I have two tanks, and both are running low nitrates lately, at about 1ppm or less by Red Sea and Salifert tests. Running about 0.2-0.5 ppm phosphates by Hanna (0.22) and Salifert (0.25-0.5).

My Evo no longer has detectable GHA or other nuisance algae and is only growing codium. Clowns are fed NLS pellets once a day and they eat a lot of them. Also feed the tank some Reef Nutrition mixture every few days.

My IM 10g has a bubble algae problem, and also grows Botrycladia, Gracilaria hayi and codium. TSB/firefish/filter feeders get TDO pellets and Reef Nutrition liquid food mixture Mon-Fri.

The combo of low NO3, high PO4 and low nuisance algae is a bit new to me--what is keeping PO4 up but NO3 so low?

Sometimes pieces of codium break off and drift into unreachable caves--is this releasing a bunch of PO4?

Thanks!

 

[blaxsun]

Could be feeding/food.

 

[Tamberav]

Fish food is full of po4 and no3 is used at a greater rate than po4 by inhabitants.