Protein skimmer size calculator
For most reefs, size the skimmer to 1.5x display gallons for light bioload, 2x for medium, and 2.5x for heavy.
Light, medium, and heavy targets are 113, 150, and 188 gallons of skimmer rating.
How to use this result and review notes
This tool is a doorway into the build planner. Use it for the quick number, then check the surrounding equipment before buying.
Reviewed by Max Rodes on 2026-05-01 against the connected guide, equipment sizing methodology, and planner formula.
Calculators expose planning assumptions, not guarantees. See the editorial policy.
What this catches
The first-order mismatch: too little capacity, unsafe wattage, weak turnover, missing coverage, or a budget that ignores supplies.
What it cannot catch alone
A single calculator cannot verify every product, livestock choice, chamber fit, vendor listing, or future stocking plan.
Why open the planner
The planner combines this result with equipment categories, budget tier, bioload, and compatibility rules.
Embed this calculator
Free to use on your site, forum post, or club page. Paste this where you want the live calculator to appear.
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