Free, instant, no-signup tools for planted-tank keepers — built on standard aquarium-keeping methods, not guesswork. Pick a tool below.
CO2 Calculator
Starting bubble rate, drop-checker targets & a livestock-safe CO2 schedule for your tank size.→
Starting bubble rate, drop-checker targets & a livestock-safe CO2 schedule for your tank size.→
EI Fertilizer Dosing Calculator
Exact KNO3, KH2PO4 & trace-mix doses in grams and teaspoons, plus the weekly EI schedule.→
Exact KNO3, KH2PO4 & trace-mix doses in grams and teaspoons, plus the weekly EI schedule.→
Aquarium Volume Calculator
Tank volume in gallons & liters, substrate, heater wattage & filter flow recommendations.→
Tank volume in gallons & liters, substrate, heater wattage & filter flow recommendations.→
Why these tools exist
Forums and blogs link to tools that save them answering the same question twice. Each calculator above encodes a standard, verifiable planted-tank method — the drop-checker method for CO2, Tom Barr's Estimative Index for fertilizers, and the textbook volume and equipment-sizing formulas — so the answers match what experienced keepers would tell you.
These calculators provide starting guidelines based on standard planted-aquarium practices, not veterinary or professional advice. Every tank is different — observe your plants and livestock, adjust gradually, and when in doubt, start lower and go slow.