Low-Yield Well Storage Tank Sizer

Free Tool

If your well runs out mid-shower, a storage tank is usually the fix. Enter your well's slow flow rate and your use, and see the two things that matter — whether it refills each day, and the tank size that gets you through the busy hours.

Your Well & Use

Tell us your numbers

Your well's flow rate (yield) A low-yield well is usually under 5 GPM. Use your flow test, or time how long it takes to fill a bucket.

1.5 GPM

That's about 2,160 gallons a day

People in the household Drives how much water your home uses in a day.

Your household's water habits Sets the gallons-per-person we use for your daily total.

Your busiest 2 hours (gallons) The morning or evening rush — showers, laundry, dishes back-to-back. A family of four often runs 250–350 gallons in that stretch.

300 gal

Your result

Refills over 24 hours?

Yes

Survives the busy 2 hours?

Recommended storage

~165 gal

Your well makes per day~2,160 gal

Your household uses per day~300 gal

Busiest 2 hrs: need vs your well300 / 180 gal

Your well refills that tank in~1.8 hrs

The two-pump fix: your well pump slowly fills a storage tank around the clock, and a separate booster pump delivers full house pressure on demand — so a 1.5 GPM well feels like city water at the tap.

Estimate only. A licensed pump pro sizes the tank, the fill pump, and the booster to your well's real flow test.

Storage fixes timing, not a true shortage

A storage tank changes when you use your water, not how much your well makes. If your well produces more than your household uses over a full day, a tank smooths out the busy hours beautifully. But if it can't make a full day's water — a true shortage — a tank only delays the problem, and you need a driller to look at deepening the well, hydrofracking, or a second well. This tool tells you which situation you're in.

The Math

Two questions, not one

Does it refill each day?

Your flow rate × 1,440 minutes is your daily output. Even a 1 GPM well makes 1,440 gallons a day — far more than most homes use. If daily output beats daily use, your well keeps up over 24 hours.

Does it survive the rush?

In your busiest 2 hours the well only adds flow × 120 minutes of water. When your rush needs more than that, the well runs dry mid-shower — that gap is the real problem, and it's what storage is for.

Size the tank to the gap

We size storage to bridge that busy-hour shortfall plus a 25% safety buffer, then round up to a standard tank. A booster pump on the tank gives you full pressure no matter how slow the well.

Sources: Penn State Extension, Using Low-Yielding Wells & Estimating Water Needs (daily output = GPM × 1,440; the 2-hour peak method; 100 gal/person storage rule; the two-pump storage-and-booster configuration); New York State Dept of Health, Water Storage Fact Sheet (storage bands for 1–5 GPM wells); Water Systems Council (booster delivery); US EPA WaterSense (per-person daily use). Planning estimates — a licensed pump pro confirms the design against your well's flow test.

Get a storage system sized and installed right

A storage tank, fill pump, and booster have to be matched to your well's real flow. Get up to 3 free quotes from licensed well & pump pros near you. Direct contact, no referral fees.

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