why won't my coral polyps open?

LPS, SPS and all coral chat
eagle
Posts: 2
Joined: Thu Oct 10, 2024 2:06 pm

why won't my coral polyps open?

Post by eagle »

My Zoanthids haven't opened in three days. Tank is a 40-gallon with two Clowns, parameters are 0 ammonia, 0 nitrite, 10 nitrate, salinity at 1.025. Lighting is AI Prime running 8 hours, no recent changes. Any ideas?
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bronx
Posts: 6
Joined: Sat Oct 14, 2023 8:40 am

Re: why won't my coral polyps open?

Post by bronx »

First, check for pests like nudibranchs or spiders. They're sneaky and can stress Zoas. Also, how's flow? Too much direct current can keep them closed. Try adjusting your powerhead.
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falconry9
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Joined: Mon May 29, 2023 9:53 pm

Re: why won't my coral polyps open?

Post by falconry9 »

Yo, eagle, what's your temp at? Sometimes a tiny dip below 76°F can mess with 'em. Also, any new fish or coral added lately? Could be a weird vibe in the tank.
Vultaen
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Joined: Thu Oct 10, 2024 2:56 pm

Re: why won't my coral polyps open?

Post by Vultaen »

falconry9 wrote: Sat May 17, 2025 11:49 am Yo, eagle, what's your temp at? Sometimes a tiny dip below 76°F can mess with 'em. Also, any new fish or coral added lately? Could be a weird vibe in the tank.
Temperature fluctuations are critical. Stable 78°F is ideal. Also, test alkalinity—Zoas hate swings. Aim for 8–9 dKH.
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JudgeRay
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Joined: Thu Oct 10, 2024 2:51 am

Re: why won't my coral polyps open?

Post by JudgeRay »

Had this happen when my skimmer went nuts and stripped organics. If you're running carbon or UV, cut it for a day. Sometimes they just need a chill period.
otterfly
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Joined: Thu Oct 10, 2024 5:08 pm

Re: why won't my coral polyps open?

Post by otterfly »

Lol, my Zoas once stayed closed for a week just 'cause I moved a rock. Drama queens! But yeah, check if they're getting enough light. Maybe shift 'em higher?
eagle
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Joined: Thu Oct 10, 2024 2:06 pm

Re: why won't my coral polyps open?

Post by eagle »

Thanks, all. Temp's steady at 78°F, no new additions. I'll check for pests and tweak flow. Alkalinity was 7.5 last test—gonna bump it slowly.
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bronx
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Joined: Sat Oct 14, 2023 8:40 am

Re: why won't my coral polyps open?

Post by bronx »

eagle wrote: Sat May 17, 2025 5:14 pm Thanks, all. Temp's steady at 78°F, no new additions. I'll check for pests and tweak flow. Alkalinity was 7.5 last test—gonna bump it slowly.
Good call. Use baking soda mixed with RODI for alk adjustments. Sudden changes freak them out.
wildfoxer
Posts: 1
Joined: Thu Oct 10, 2024 6:42 pm

Re: why won't my coral polyps open?

Post by wildfoxer »

Mine did this when phosphates spiked. You running GFO? Might be worth a check.
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dorvil9
Posts: 10
Joined: Thu Oct 10, 2024 12:24 am

Re: why won't my coral polyps open?

Post by dorvil9 »

Aye, eagle, how old's your salt mix? Sometimes stale salt messes with trace elements. Just a thought.
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