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My corals aren't growing like they used to. I've been keeping my pH around 8.0, but I'm not sure if that's the sweet spot. What's the ideal range for most corals? My tank's a 50-gallon with T5 lighting, running a protein skimmer, and I do weekly 10% water changes with Red Sea salt.

8.0 is decent, but most corals thrive at 8.1 to 8.4. Stability matters more than hitting a perfect number though. What's your alkalinity at? If it's swinging, that could be the real issue. I keep mine at 8.3 with a dosing pump and my Acros love it.

Yep, reef9's spot on. Gotta keep that alk steady too. My tank's at 8.2, and the Zoas are popping. You using a controller? Makes life easier if you're messing with pH. I've got a Neptune Apex keeping things chill.

reef9 wrote: ↑Thu Aug 28, 2025 3:02 am 8.0 is decent, but most corals thrive at 8.1 to 8.4. Stability matters more than hitting a perfect number though. What's your alkalinity at? If it's swinging, that could be the real issue. I keep mine at 8.3 with a dosing pump and my Acros love it.

Exactly this. pH is part of the puzzle, but alk and calcium are just as key. My SPS tank runs at 8.3, alk at 8.5 dKH, and I dose daily. How often are you testing?

Honestly, if your pH is stable at 8.0 and everything else is in line, I wouldn't stress. My softies do fine at 8.0, but my LPS prefers 8.2. What corals are you keeping? That'll change the game. Also, what's your tank's CO2 like? High indoor CO2 can drag pH down.

Thanks for the input, everyone. I'll test alk and calcium more often. Mostly keeping LPS and softies right now, with a couple of Montiporas. Tank's near a window, so CO2 might be a factor.

Window could be sketchy for temp swings too. My pH dips at night, but it's normal. You got a refugium? Macroalgae can help stabilize things. I run chaeto on a reverse light cycle, keeps my pH from crashing.

I've had luck at 8.1 with my mixed reef. Nothing fancy, just a HOB filter and weekly water changes. My Duncan's been growing like crazy. Maybe try bumping it up slowly? Sudden changes freak corals out.

My two cents: if your corals look happy, don't fix what ain't broke. My pH sits at 8.0, and everything's thriving. But I'm lazy with testing, so take that with a grain of salt. Literally.

graye wrote: ↑Thu Aug 28, 2025 6:52 am Honestly, if your pH is stable at 8.0 and everything else is in line, I wouldn't stress. My softies do fine at 8.0, but my LPS prefers 8.2. What corals are you keeping? That'll change the game. Also, what's your tank's CO2 like? High indoor CO2 can drag pH down.

Yeah, CO2's a sneaky one. I cracked a window near my tank, and pH went up 0.2. Cheap fix if that's your issue.