Nutrient question

USMA36 · Sep 28, 2017

I run a 90 gallon mixed reef tank about 7 months old. Last month I switched from a sing radion g3 pro to an ATI 36” sunpower. For the longest time I was battling high phosphates (.9). I started running GFO but I was exhausting it every 3 or 4 days. I added chaeto to my sump in an 8ish gallon section. Started off with a softball and now about 5 weeks later it’s the size if a basketball. I tested my phosphates with a Hannah checker and it comes up all zeros and nitrates came back 0 as well. Its been about 2 weeks since my last water change and I am going to start the Triton for other methods this week. I know there must be some phosphates as I have a few small patches of green bubble algae and some other algae on one of my return nozzles. What should I do? Tank looks decent for something new (at least I think so) fish look happy and corals are growing. I started adding reef chili and I think thats what caused the spike in Green bubble algae. My Alk is steady at 8.3, Calcium around 440, and pH runs between 7.85 to 8.15. Should I feed more? Keep up with the reef chili and just manually get rid of the bubble algae as it appears? Don’t dona water change? Should I stop the GFO or in less of it? I don’t get much algae on the glass. I run a magnet over 2 or 3 times a week at most. Here’s a crappy cell phone picture.

CodyRVA · Sep 28, 2017

Are you target feeding the reef chili or just dosing it? Personally, I would at least try stop using the reef chili and see how your tank responds then take additional action if needed. Change one thing at a time, inspect, and repeat. How are you using your gfo? When I test out at 0 PO4 and I have GFO on my system, I turn the valve down so it tumbles less; same thing when I test a bit high, i just open the valve more so it tumbles more and replace the media once a month. GFO is great, but you don't want to strip your system so be careful.

FWIW I used to spot feed my coral and stopped, legit see no difference. Of course this depends on the specific coral and how much you want to encourage growth rates, but yea... If you have algae, you probably have enough nutrients to feed your corals. Lastly, PO4 takes a WHILE to truly be extinguished once you push it so high. Mine hit .75 (hanna ULN checker) so I ran GFO and within about 10 days it read 0. Took the GFO off, tested a few days later and it jumped back up even after monitoring feeding very closely... PO4 can linger so keep an eye on it.

roberthu526 · Sep 30, 2017

Bubble algae is not a indication of nutrient problem. It doesn't just appear. It mist have come from one of your frags. You will have to manually remove it. Or you can try your luck with emerald crab.