Alex,
I would like to suggest another option that I am using on my pool. Have a look at a Pulastron Pump. It seems to be doing a great job of maintaining my FC without having to do a manual add everyday. I had the pump left over from another job and thought it might work, so I got a large 8 gal bucket with a locking lid, drilled a small hole in the side near the top and installed the feed line from the bucket to the pump and then ran a line up to the pool and zipptyed it to the hose for my robot cleaner. I am still slowly dialing it back to drop my FC level down, but other than topping off the bucket with 8.25% clorine once a week, and testing each day till I get it down to the FC level that I want, it has been worry free and worked great. I do have it set up on the same timer as my main pool pump so it only adds when the water is filtering but I don't think the small amount that it dumps in each stroke would really hurt anything even if the pool pump wasn't working. I guess ta mate it is putting out about 2 cc per pulse for about 6 hrs total per day.
Total cost for new Pulsatron about $300 plus a white bucket with locking lid free from work, bucket might cost you $10-15.
It comes with about 10ft of hose and a checkvalve with a filter for the supply side.
It even says it is for outdoor use on pools and spas.
Just one other option for you to look at.
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