Feedback: Draining and Refilling Is Not Costly

[Re: How to Lengthen the Life of Hot Tub Water February AQUA]

Please, dispel the myth that draining and refilling a hot tub is “costly.” I find the No. 1 misconception among my customers is how much it really costs to drain and refill a hot tub.

I tell all my customers: “You can buy chemicals that will solve just about any water quality problem temporarily, but it’s nearly always cheaper and more effective to start with fresh, clean water.”

Here in San Diego the water rates are as follows.


The bi-monthly charges for a typical single-family domestic customer are:

Base fee: $38.66First 14 HCF used are billed at $3.612 per HCF.Second 14 HCF used are billed at $3.917 per HCF.Each HCF used after the initial 28 HCF is billed at $4.398 per HCF.

Even if you apply the highest rate per HCF (748 gallons), it costs less than $3.00 to fill a 500-gallon hot tub. Even if the wastewater (sewer) rate doubles the cost, it still only costs around $6 to drain and refill a 500-gallon tub.

If you assume a 5.5kW heater will add about 5 degrees per hour (see Raypak heating calculator), it costs $10 to $15 in electricity to reheat a newly filled hot tub here in San Diego.

Round up to maybe $25 to drain, refill and reheat a tub here in Southern California where we pay some of the highest rates for water and electricity. You can hardly get out of a pool or spa store with less than $25 in chemicals.

Of course, there is the cost of start-up chemistry but, overall, a drain-refill is usually more effective in both cost and results than just dumping more and more chemistry in the tub.

You should also point out the water in any hot tub is recycled more than any other drop of water in the house. The average full-size, super-duty washing machine uses 55 gallons per load and every drop of that water goes straight down the drain.

A 500-gallon hot tub represents less than 10 full-sized loads of laundry and most tubs these days hold less than 500 gallons. The idea of keeping water for a year or longer is often perpetuated by poorly informed sales people trying to overcome the objection that water quality takes a lot of work.

Tom Davis, Owner  | Affordable Hot Tub Repair, San Diego, Calif.

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