Pool, Spa & Water Treatment Chemistry calculator

Chlorine Tablet Feed Rate Calculator

Chlorine tablet feed rate estimates how many trichlor tablets per day your pool consumes to hold free chlorine against daily demand. Pool techs use it to set an erosion feeder or chlorinator dial correctly instead of guessing, which prevents both algae from underfeeding and stabilizer creep from overfeeding. It ties together your pool size, how fast the water burns chlorine, each tablet's ppm yield, and how efficiently your feeder dissolves them. Set the feed rate right and the pool holds a steady chlorine level with far less hands-on dosing.

What this calculator does

  • Estimate chlorine tablet feed rate from pool volume, daily chlorine demand, tablet yield, and feeder efficiency.
  • Use it to plan trichlor feeder settings, route inventory, or expected tablet consumption.
  • It estimates the number of chlorine tablets per day needed to meet your pool's daily chlorine demand, adjusted for feeder efficiency.

Formula used

  • Tablet feed rate = pool volume basis x daily demand x tablet demand factor x feeder efficiency adjustment

Inputs explained

  • Pool volume basis: Divide pool gallons by 10,000. For a 20,000-gallon pool, enter 2.
  • Daily free-chlorine demand: Estimate from test history, sun exposure, bather load, and time of year.
  • Tablet demand factor: Enter 1 divided by tablet ppm yield per 10k gal. For 1.8 ppm per tablet, enter 0.56.
  • Feeder efficiency adjustment: Enter 100 divided by feeder efficiency percent. For 85% feeder efficiency, enter 1.18.

How to use the result

  • Use it when setting up or dialing in an erosion feeder or floating chlorinator for hands-off daily sanitizing.
  • Trichlor tablets add cyanuric acid with every dose, so a feed rate correct for chlorine today will slowly over-stabilize the pool and eventually require a partial drain.

Current U.S. benchmarks

  • Global copper trades at $13,552 per tonne (IMF via FRED, Jun 2026), up 37.8% in a year, and U.S. industrial electricity averages 8.66 cents per kWh. Both feed electrified-hardware unit economics.

Common questions

  • How do you calculate chlorine tablet feed rate? Multiply pool volume in 10k-gallon units x daily ppm demand x the tablet demand factor x the feeder efficiency adjustment. Our example works out to about 2.64 tablets per day.
  • How many chlorine tablets per day does a pool need? It depends on size and demand. A 20,000-gallon pool losing 2 ppm/day needs roughly 2-3 three-inch tablets daily, matching our 2.64-tablet example.
  • What is daily chlorine demand? The ppm of free chlorine your pool loses each day to sun, bathers, and organics. Sunny summer pools with heavy use can burn 2-4 ppm per day.
  • What is the feeder efficiency adjustment? It is 100 divided by your feeder's efficiency percent. An 85% efficient feeder gives 1.18, bumping the tablet count up to cover incomplete dissolution.
  • Do chlorine tablets raise cyanuric acid? Yes. Trichlor tablets add cyanuric acid with every tablet, so steady feeding slowly raises stabilizer and eventually calls for fresh water to reset it.

Last reviewed 2026-05-12.