Maintaining calcium in small tanks

LPS, SPS and all coral chat
xterrab
Posts: 4
Joined: Thu Oct 10, 2024 10:28 pm

Maintaining calcium in small tanks

Post by xterrab »

I've got a 10 gallon tank with a few soft corals and LPS, but my calcium levels keep dropping fast. I'm dosing manually but it's a hassle. Anyone got tips for keeping it stable without daily dosing?
deepstar1
Posts: 5
Joined: Thu Oct 10, 2024 3:12 pm

Re: Maintaining calcium in small tanks

Post by deepstar1 »

Small tanks are tricky since params swing faster. What's your alk at? If it's low, calcium won't stay put. I'd test alk first, then maybe switch to a two-part doser. I use the BRS ones on my 15 gallon, keeps things steady for weeks.
daxilix
Posts: 10
Joined: Thu Jan 25, 2024 10:11 am

Re: Maintaining calcium in small tanks

Post by daxilix »

yo, i just throw in some crushed coral in the filter. seems to work, but my tank's only 5 gallons. dunno if it'll cut it for you.
folksy9
Posts: 5
Joined: Thu Oct 10, 2024 4:42 pm

Re: Maintaining calcium in small tanks

Post by folksy9 »

daxilix wrote: Tue Sep 16, 2025 12:26 pm yo, i just throw in some crushed coral in the filter. seems to work, but my tank's only 5 gallons. dunno if it'll cut it for you.
Crushed coral's a decent idea, but it's slow. If you're dosing already, maybe try a kalkwasser stirrer. Heard those are solid for small setups.
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bronzeoak
Posts: 14
Joined: Fri Jan 28, 2022 5:47 am

Re: Maintaining calcium in small tanks

Post by bronzeoak »

I had the same issue in my 12 gallon. Switched to a nano calcium reactor and it's been smooth sailing. Pricey upfront, but worth it if you're serious about keeping LPS.
Trims
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Joined: Thu Oct 10, 2024 9:29 pm

Re: Maintaining calcium in small tanks

Post by Trims »

how often you testing? my 10 gallon's chill with weekly water changes, no extra dosing. maybe your salt mix is low on calcium?
ottero
Posts: 7
Joined: Thu Oct 10, 2024 7:58 pm

Re: Maintaining calcium in small tanks

Post by ottero »

Trims wrote: Thu Sep 18, 2025 7:06 am how often you testing? my 10 gallon's chill with weekly water changes, no extra dosing. maybe your salt mix is low on calcium?
Good point. I use Red Sea Coral Pro, and it's packed with calcium. Maybe switch salts if you're using something basic.
xterrab
Posts: 4
Joined: Thu Oct 10, 2024 10:28 pm

Re: Maintaining calcium in small tanks

Post by xterrab »

Thanks for the advice, everyone. I'll test my alk and look into a two-part doser or kalkwasser. Appreciate the help!
xterrab
Posts: 4
Joined: Thu Oct 10, 2024 10:28 pm

Re: Maintaining calcium in small tanks

Post by xterrab »

Thanks for the advice, everyone. I'll test my alk and look into a two-part doser or kalkwasser. Appreciate the help!
deepstar1
Posts: 5
Joined: Thu Oct 10, 2024 3:12 pm

Re: Maintaining calcium in small tanks

Post by deepstar1 »

xterrab wrote: Thu Sep 18, 2025 11:57 am Thanks for the advice, everyone. I'll test my alk and look into a two-part doser or kalkwasser. Appreciate the help!
No problem. Let us know how it goes. Also, check your magnesium levels—low mag can mess with calcium uptake too.
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