Id recommend getting Microbe Lift Special Blend if you’re looking to lower nitrates.
It has photosynthetic bacteria, your typical nitrifying aerobic bacteria, and uniquely, anaerobic bacteria that will help transform your nitrates into nitrogen gas.
I would slow down on NoPox as I’m sure it’s fueling your bacteria culture, which is why your nitrates might be high as it’s breaking down all the nutrients, but not facilitating export of nitrates.
I agree with others, increase your water change to 30% daily until your nitrates are in the range you desire, but remember WWC and most retail companies keep their nitrates high at around 20-25 which is also where I keep mine at.
The moment you drop nitrates is when most tanks begin to crash leading to bacterial die offs, dinoflagellates, bleaching or corals getting paler, etc so do it slowly.
Feeding fish food will definitely get phosphates up, but frozen food would provide less P than dry or pellets.
Dosing phosphates would help balance and encourage the lowering of nitrates so:
1. attempt dosing at 50% dose of NeoPhos and measure until you’ve reached your desired level
2. Try diversifying bacterial culture with Special Blend Micro-Lift
3. Incorporate water change 20-30% until nitrates drop
4. Try reverse photo-period light cycle on refugium
5. Make sure not to run GFO or change carbon to avoid striping nutrients during this process
6. Be careful carbon dosing and bacteria bloom/oxygen deprevation
7. Avoid cleaning the sandbed since that’s where most anaerobic bacteria thrive and may release nitrates back into the water column
8. Measure daily and keep us updated!