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My SPS corals are showing signs of stress, and I suspect high nitrates might be the issue. Currently running a 75-gallon tank with a protein skimmer, weekly 15% water changes, and nitrates hovering around 20 ppm. What's the most effective way to bring them down without shocking the system?

I've had luck with chaeto in a refugium. It's pretty chill and doesn't mess with the tank vibe. Just gotta keep the light on reverse cycle. What's your lighting setup like?

daisys wrote: ↑Mon Jul 21, 2025 1:57 am I've had luck with chaeto in a refugium. It's pretty chill and doesn't mess with the tank vibe. Just gotta keep the light on reverse cycle. What's your lighting setup like?

Chaeto's solid, but if you're not running a refugium, carbon dosing with vodka or vinegar can work. Start slow, like 0.1 mL per 25 gallons, and monitor nitrates daily. Overdoing it can crash your tank.

I'd skip the carbon dosing if you're not comfy with the risks. More water changes are safer. Bump it to 20% twice a week and see if that cuts it. Also, how often are you feeding? Overfeeding's usually the culprit.

Agree with SunDay. I had a similar issue in my 50-gallon. Cut feeding to every other day and upped water changes. Nitrates dropped to 10 ppm in two weeks. What coral species are we talking about?

Thanks for the suggestions. I'll try increasing water changes first. Running a mix of Acropora and Montipora, so they're pretty sensitive.

Yo, if you're gonna go the chaeto route, make sure your skimmer's dialed in. Skim wetter to pull more gunk out. Also, check your RODI water—sometimes the TDS creeps up and adds to the nitrate load.

I'm new to this, but my LFS told me to use nitrate pads in the filter. Worked for my softies, but not sure about SPS. Anyone tried those?

Nitrate pads can help short-term, but they're not a fix. You gotta address the root cause. Like others said, feeding and water changes are key. What's your current nitrate level?

Bruh, just add more live rock. The bacteria will handle it. No need to overcomplicate things.