SPS stopped growing

Xandernfs · Mar 1, 2019

I have a feeling it is due to my parameters, but I just wanted to double check with you all. My SPS isn't really doing much growing lately. All the corals (few acro, stylo, birdsnest, montis) look great and have great polyp extension, but they aren't really growing. They are more along the lines of just 'living'. I know it's not due to the lighting since I'm running my ap700 at 50% along with 4 T-5 bulbs. This is all over my RSR250. My parameters are as follow:

NO3 - 0-.2
PO4 - 0-.01
ALK - 9.0-9.5 (manual dosing daily)
Ca - 400-420 (Weekly dosing)
Mg - 1650

I used to keep my ATS light on 24/7, but I have started to reduce it to 18 hours a day. Should I alter it more? I also only have 4 fish in the tank. I'd like to add more fish, but haven't had the time to go to the LFS. Like I said, I think my NO3 & PO4 are probably too low. I have been dosing Reef Energy, but not to the extent of what they recommend as an ULNS. What are your thoughts on how I should tackle this?

McPikie · Mar 1, 2019

4 fish is very low stock. I'd up that first. Maybe dose Nitrate until then?

Gregg @ ADP · Mar 1, 2019

I will utter words never heard in reefing back in the 90s-early ‘00s:

Get your nitrates and phosphates up.

Justin Cook · Mar 1, 2019

What kind of test kit are you using? I use salifert for both of those and it's very, very hard to distinguish what the actual levels are when they're low. Personally, I'm going to move to Hanna but if my tests read like yours, I might try to get my nitrate up and let the phosphates be and see if that helps.