Best 90-gallon aquariums for large community or mbuna or mixed reef. Top picks across budget tiers, what livestock fits, what to avoid, dimensions, weight, and FAQ. Updated May 2026.
Premium clear-glass option.
Standard rimmed.
Premium reef AIO with sump.
Suitable:
Avoid:
Beyond the tank itself, you'll need:
Use the stocking calculator to verify your livestock plan, the weight calculator to confirm your floor can handle it, and the electricity calculator for ongoing operating cost.
Standard 90-gallon aquarium dimensions: 48"×18"×24" or 36"×18"×30". Filled weight ~900 lbs.
~900 lbs filled (tank + water + sand + rock). Standard residential floors support ~40 lb/sq ft live load - tanks of 90g+ should be placed over a load-bearing wall or perpendicular to floor joists.
Yes - small marine setups (FOWLR or nano reef) work in 20g+. The reef setup options for this size are documented on the 20g FOWLR setup guide.
Total 90-gallon build cost varies by tier: budget $540-1080, mid $1080-2250, premium $2250-4500+. Use the reef build calculator for detailed breakdown.
Browse the full aquarium-by-size buying guide for 11 other tank sizes. Or jump to the step-by-step setup guides, the stocking blueprints, or the calculator collection.
Equipment is where you allocate budget for stability. The cheapest pump runs hot + dies in 18 months; a quality pump runs cool for 8-10 years. The math on equipment is dramatic: a $400 quality canister filter beats four $100 cheap canisters across a decade, plus saves you the maintenance headaches + livestock losses from failures.
Three principles for equipment selection: 1) Oversize for the job - rated GPH is always inflated by 30-40%; size everything for the worst-case load. 2) Brand-name over no-name - established brands (Eheim, Sicce, EcoTech, Tunze, Hydor, Reef Octopus, Fluval) have parts available + service centers. 3) Plan for redundancy - 2 smaller heaters beat 1 large one (if one sticks, the other still works + the controller catches it).
For purchase planning, use our equipment budget builder, heater wattage calculator, protein skimmer sizing, and filter turnover calculator.
Should I buy used equipment? Yes for tanks + stands + plumbing (inspect for cracks). No for pumps + heaters + UV bulbs (unknown remaining life). Maybe for skimmers if you can clean + verify.
How long should equipment last? Quality heaters: 2-3 years (replace preventively). Pumps: 5-10 years. Skimmers: 10+ years (replace pump every 3-5). Filters: 10+ years (rebuild seals every 3-5). LED fixtures: 5-7 years.
Wattage vs gallons rule for heaters? 3-5W per gallon for cool rooms, 1-3W per gallon for warm rooms. Use 2x smaller heaters for redundancy + safety. See heater wattage calculator.
Sump or HOB filter? HOB for tanks under 40g (cheap, easy). Canister or sump for 40g+ (better filtration capacity, room for media customization). Sump required for 75g+ reef.
What about controllers (Apex, Inkbird)? Inkbird ($30-50) for any tank - protects from heater failure. Apex ($400-800) for SPS reef + dosing automation + Wi-Fi alerts. Worth every penny.
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