I have a 150 cube that is 95% acropora. It has been up a few months. The system is relatively simple for nutrient control... skimmer, big refugium with powerful horticulture LED and 10-15% weekly water changes.
Last week I switched from LED to halide. My phosphate has jumped from 0.12ppm to 0.38ppm (hanna ULR phosphorous) over the last 7 days. I THINK this is because I was running a 9AM-11PM photo period with the LED and I reduced it to noon-4PM when replacing the LED with halide. I have added 30 min every day since last friday to the photoperiod of the halide. I think the reduced photoperiod in the display caused some film algae death or something which spiked phosphates. There's really no other explanation for phosphate to jump that high as I have changed nothing else at all. Nitrates have been 16-32ppm on the red sea kit over this same 7 day time period. They are possibly slightly more toward the 32 than the 16 this week however.
Here's my dilemma. I could turn up my refugium photoperiod, but I'm afraid of starving the acropora. Even though the test kits show high nutrients I honestly feel like in the past when I increase my refugium photoperiod, even though the nutrients either stay the same or only go down slightly, my acropora takes a hit. It's like they chaeto consumes the organic form of the nutrients faster than acropora can and even though numbers are there on the test kit it's not showing the whole story...
I'd love to hear everyones' thoughts on this.
Last week I switched from LED to halide. My phosphate has jumped from 0.12ppm to 0.38ppm (hanna ULR phosphorous) over the last 7 days. I THINK this is because I was running a 9AM-11PM photo period with the LED and I reduced it to noon-4PM when replacing the LED with halide. I have added 30 min every day since last friday to the photoperiod of the halide. I think the reduced photoperiod in the display caused some film algae death or something which spiked phosphates. There's really no other explanation for phosphate to jump that high as I have changed nothing else at all. Nitrates have been 16-32ppm on the red sea kit over this same 7 day time period. They are possibly slightly more toward the 32 than the 16 this week however.
Here's my dilemma. I could turn up my refugium photoperiod, but I'm afraid of starving the acropora. Even though the test kits show high nutrients I honestly feel like in the past when I increase my refugium photoperiod, even though the nutrients either stay the same or only go down slightly, my acropora takes a hit. It's like they chaeto consumes the organic form of the nutrients faster than acropora can and even though numbers are there on the test kit it's not showing the whole story...
I'd love to hear everyones' thoughts on this.