Every number for a healthier tank
Size your tank, heater, filter, stocking, and water changes in seconds, then back it up with straight-talking fishkeeping guides and gear picks. Freshwater and saltwater.
Length
48 in
Width
18 in
Height
21 in
75 gallons
284 L · ~750 lb filled
Most-used calculators
Tap a tool, enter your numbers, get an answer plus the gear that fits.
Explore the whole hub
Calculators
18 free tools to size your tank and gear.
Explore → 🐠Fish Species
Care, tank size, and tankmates by species.
Explore → ⭐Gear Reviews
Filters, heaters, lights, test kits, and more.
Explore → 💧Water & Care
Cycling, parameters, algae, and maintenance.
Explore → 📊Reference Charts
Quick-look tables you can bookmark.
Explore → 🛟Troubleshooting
Fix cloudy water, sick fish, and more.
Explore →Sized to real equipment
Our calculators do not just spit out a number, they translate it into the heater wattage, filter flow, and gear that actually fits your tank.
Freshwater and saltwater
From a first betta tank to a reef build, the tools and guides cover community, planted, and marine setups.
No fluff, no fear-mongering
Clear, practical advice grounded in how fishkeeping actually works, so you can make confident decisions fast.
Aquarium Setup & Maintenance Planner
Stocking planner, water-test log, cycling tracker, maintenance schedule, and more, in one printable PDF that keeps your tank on track.
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