Essentially it is the same concept as a pool, except everything is more touchy.
My pool is 17,000 gal. My hot tub is 300. That is almost 60 times smaller. Two people in my hot tub for 30 minutes is like 120 people in my pool for 30 minutes, or 60 people in there for an hour.
Things get dirtier much faster. Also, your chemical additions have to be more accurate. I was used to adding acid by the quart to my pool. I add acid by the ounce in my hot tub.
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