I understand the Stenner prefers to run at a high speed for a short time.
That tends to be true...although I think plenty of people use the variable ones and don't run them at full...but running them at full is supposedly better for them and doesn't have the clicking sound. IMHO, if you're going to run it at full anyway, just get a non-adjustable one and control it purely via runtime which is what I plan to do when I get around to it (and convince the wife).
My current July average daily demand for 8.25% chlorine is 70 to 80 oz per day with CYA of 50. It can get hotter in August so I would have to allow for that. I have an Easy Touch 4 which I think I can add the pump to and run it while the pool is running, but if not, I will get it a separate timer.
I am not sure which Stenner pump would be suitable for my size of pool and spa. Any advice would be welcome.
Generally I think the 10 GPD (gallons per day) models are most-commonly used around here. For non-adjustable, that's either the 45MPHP10 (up to 100psi) or 45MP2 (up to 25psi) depending on the pressure of your system. They smaller 3 GPD ones would require pretty substantial runtime, and the larger ones are probably too fast (you don't want almost pure bleach coming out of your returns =p).
You need ~75 oz per day and so that's 75 / 128 == 0.5859375 gallons per day. Since the pump is 10 gallons per day, you need 0.5859375 / 10 == 0.05859375 == 5.859375% of its daily output, and so you should run it for that percentage of the day. So 24 hours * 60 minutes/hour * 0.05859375 == 84.375 minutes...which you could probably safely round down to 80 or up to 90 (since you'll still be testing FC levels regularly and can make subtle adjustments or manually run the pump for a bit).
So you need ~84 minutes per day, you can either run it straight 84 minutes or break that up. One solution might be to run it for an 60 minutes in the evening (since it's better to add chlorine after swimmers/sun are gone) and let it work all night...and then run it 24 minutes in the morning to prop levels back up for the next day's activity. It doesn't really matter...whatever you think works best.
As an aside, in your pool (13.2 K gallons) it's about 20oz of your 8.25% bleach to get 1ppm FC...the pump would inject those 20oz in 22.5 minutes...so if you wanted like a quick boost before/after a big party, you could manually run the pump for 45 minutes.
Hope all that makes sense!
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At 10 gallon a day flow rate, I have a 35 minute run time per day.
31oz a day for only 1.25 FC per day...that's a well managed pool especially for sunny Florida. Totally agree with fixed vs adjustable and 26rpm vs 44rpm...the 45MPHP10 is also the one I'm planning to get.
