pH swings affecting corals

[florian]

My tank's pH keeps swinging between 7.8 and 8.4, and my Acropora are looking stressed. Running a 75-gallon with T5 lighting, weekly 10% water changes, and a Reef Octopus skimmer. Anyone dealt with this before?

[FableKing]

pH swings that large can definitely stress SPS. First, check your alkalinity levels—they should be stable around 8–9 dKH. Also, are you dosing anything? A calcium reactor or kalkwasser can help stabilize pH if set up correctly.

[buddyx]

Yep, had the same issue last year. My Torches started retracting, and the Zoas closed up. Turned out my CO2 levels were too high from poor room ventilation. Maybe test your room's air?

[sealux]

I agree with FableKing. Alkalinity is key. My tank runs a Neptune Apex to monitor pH and dose buffers automatically. It's pricey but worth it for SPS.

[cleverfox]

How's your surface agitation? Low flow at the top can cause CO2 buildup, leading to pH drops. Try pointing a powerhead upward or running an air stone at night.

[florian]

Thanks for the tips. I'll test alkalinity tonight and adjust my powerheads. Didn't think about room CO2 being a factor.

[rivetax]

Dude, my pH was all over the place till I started using a fuge with macroalgae. Chaeto sucks up CO2 like crazy, and it's cheap to run. Just a thought.

[bronzeo]

pH swings that large can definitely stress SPS. First, check your alkalinity levels—they should be stable around 8–9 dKH. Also, are you dosing anything? A calcium reactor or kalkwasser can help stabilize pH if set up correctly.

Spot on. I'd also recommend a two-part dosing system if you're not ready for a reactor. It's easier to tweak.

[FableKing]

Dude, my pH was all over the place till I started using a fuge with macroalgae. Chaeto sucks up CO2 like crazy, and it's cheap to run. Just a thought.

Macroalgae helps, but it's not a standalone fix for large swings. Pair it with proper buffering for best results.

[buddyx]

Another weird thing—my pH stabilized when I switched salt mixes. Some brands buffer better than others. What salt are you using?