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What's the ideal nitrate range for keeping Acropora thriving? My tank's sitting at 15 ppm, but I've heard mixed opinions on whether that's too high. Running a 75-gallon with T5 lighting, weekly 10% water changes, and a protein skimmer.

15 ppm's pushing it for Acros, dude. I keep mine under 5 ppm, or they start looking sketchy. What's your alk at? If it's unstable, high nitrates will mess with 'em even more. My Red Sea test kit shows 7 dKH, and I dose daily.

Tagword, I've had success with 10 ppm for hardy SPS like Montipora, but Acros are fussier. Try cutting back feeding or increasing skimmer runtime. What's your current coral lineup besides the Acros?

Thanks for the input. I've got a mix of Zoas, Hammers, and the Acros. Gonna test alk tonight and maybe up the water changes to 15%.

tagword wrote: ↑Fri May 09, 2025 3:15 pm Thanks for the input. I've got a mix of Zoas, Hammers, and the Acros. Gonna test alk tonight and maybe up the water changes to 15%.

Smart move. Zoas can handle higher nitrates, but those Hammers might bail if things swing too fast. How old's the tank?

My Acros thrive at 2-3 ppm, but it's a balancing act. If you're running carbon, check that too. Old media can leach junk back into the water. I swap mine every 3 weeks like clockwork.

I'm new to SPS. Does nitrate affect LPS the same way? My Duncan's been happy at 20 ppm, but now I'm worried.

duskrid wrote: ↑Fri May 09, 2025 5:02 pm I'm new to SPS. Does nitrate affect LPS the same way? My Duncan's been happy at 20 ppm, but now I'm worried.

Nah, Duncans are tanks. They'll chill in dirtier water than SPS. But if you wanna add Acros later, start dialing it down now.

Tagword, what salt mix are you using? Some brands run high in nitrates straight outta the bag. I switched to Red Sea Blue Bucket and saw a drop.

My LFS told me under 10 ppm is safe, but my Acros browned out at 8. Maybe it's the combo with phosphates? Mine's at 0.03 ppm.