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My phosphates are creeping up to 0.15 ppm and I'm seeing some algae growth. Running a 75-gallon mixed reef with two clowns, a yellow tang, and a cleanup crew. Using a protein skimmer and weekly 10% water changes with Red Sea Coral Pro salt. Any tips to get it under control without nuking my corals?

Yo, I feel you on the algae struggle. Had the same issue in my 40 breeder. Switched to feeding every other day and added a GFO reactor. Phosphates dropped to 0.03 ppm in like two weeks. Corals didn't even blink.

Beezy wrote: ↑Sat May 10, 2025 3:14 am Yo, I feel you on the algae struggle. Had the same issue in my 40 breeder. Switched to feeding every other day and added a GFO reactor. Phosphates dropped to 0.03 ppm in like two weeks. Corals didn't even blink.

GFO's a solid move. Just don't go too aggressive with it or you'll strip everything too fast. I'd start with half the recommended dose and monitor your SPS. They're the first to throw a fit if things swing hard.

What's your lighting schedule like? I found cutting my photoperiod by an hour and adding more flow near the sandbed helped keep detritus from settling. Also, are you rinsing frozen food before feeding?

Man, my phosphates were wild until I started using PhosGuard in a media bag. Tossed it in the back chamber of my AIO and boom, problem solved. Just don't forget to replace it every month or it'll stop working.

Aurorae wrote: ↑Sat May 10, 2025 5:11 am What's your lighting schedule like? I found cutting my photoperiod by an hour and adding more flow near the sandbed helped keep detritus from settling. Also, are you rinsing frozen food before feeding?

Rinsing food's a game-changer. I use a fine mesh net and RO water. Cut my phosphates by half just from that. Also, check your RODI water—sometimes the membrane's shot and you're adding phosphates without knowing it.

I'm kinda new to this, but my LFS told me to try more snails. Got like 10 trochus and they're going ham on the algae. Phosphates are still there but at least the tank looks cleaner while I figure it out.

If you're running carbon, switch to a high-quality one like Rox 0.8. Cheap carbon can leach phosphates. Also, test your salt mix straight out of the bucket—some brands have detectable levels. And +1 to the GFO suggestion, but ramp up slowly.

How often are you cleaning your skimmer? A dirty skimmer can stop pulling gunk efficiently. I wipe mine down weekly and empty the cup every other day. Seems to help keep things stable.

Thanks for all the advice, everyone. Gonna start with rinsing food and adding a bit of GFO. I'll report back in a week or two.