Smallest saltwater tank setup

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ironix
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Joined: Thu Feb 17, 2022 5:57 am

Smallest saltwater tank setup

Post by ironix »

What's the smallest saltwater tank you've successfully kept? I'm thinking of setting up a nano reef but worried about stability. Any tips for a beginner?
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eaglebay
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Joined: Wed May 18, 2022 8:07 pm

Re: Smallest saltwater tank setup

Post by eaglebay »

I've run a 5-gallon nano reef for years. Key is consistency, water changes, and a good light. You'll need a heater, small powerhead, and live rock. Avoid fish, stick to inverts like snails or a shrimp.
kalixi
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Joined: Thu Oct 10, 2024 10:08 pm

Re: Smallest saltwater tank setup

Post by kalixi »

A 10-gallon is more forgiving than a 5. Parameters swing less, and you can maybe add a small clownfish. Just gotta stay on top of testing, especially salinity and nitrates.
slateo
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Joined: Thu Oct 10, 2024 3:21 pm

Re: Smallest saltwater tank setup

Post by slateo »

My buddy tried a 3-gallon pico reef. Crashed in a month. Not worth the headache unless you're glued to it 24/7. Go bigger if you can.
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rivulet
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Re: Smallest saltwater tank setup

Post by rivulet »

eaglebay wrote: Fri Jul 11, 2025 12:25 pm I've run a 5-gallon nano reef for years. Key is consistency, water changes, and a good light. You'll need a heater, small powerhead, and live rock. Avoid fish, stick to inverts like snails or a shrimp.
Agree with this. I'd add that auto-top off helps a ton with evaporation in tiny tanks. Salinity swings are brutal.
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burblefox
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Joined: Wed Oct 09, 2024 10:39 pm

Re: Smallest saltwater tank setup

Post by burblefox »

I've seen 2.5-gallon tanks with just a hermit crab and some macroalgae. It's doable but not ideal. You'll need to test water every other day.
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Aurion
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Joined: Thu Oct 10, 2024 1:40 am

Re: Smallest saltwater tank setup

Post by Aurion »

Why not start with a 20-gallon? More room for error, and you can actually keep a fish or two. Nano tanks are cool but kinda sketchy for beginners.
foggy_mind
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Joined: Thu Oct 10, 2024 5:21 pm

Re: Smallest saltwater tank setup

Post by foggy_mind »

If you're set on small, get a quality all-in-one like the Fluval Evo. Comes with everything you need, just add rock and water. Less guesswork.
fungielle
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Joined: Thu Oct 10, 2024 9:56 pm

Re: Smallest saltwater tank setup

Post by fungielle »

Smallest I'd recommend is 10 gallons. You can keep a pair of clownfish or a goby. Just be prepared for frequent maintenance and testing.
haywire
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Joined: Mon Sep 16, 2024 4:03 am

Re: Smallest saltwater tank setup

Post by haywire »

Aurion wrote: Fri Jul 11, 2025 4:29 pm Why not start with a 20-gallon? More room for error, and you can actually keep a fish or two. Nano tanks are cool but kinda sketchy for beginners.
Yep, 20's the sweet spot. Nano's gonna test your patience unless you're really committed.
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