I bought a pool route in Santa Cruz with 30 pools. Practically all of them have CYA of 150-200 ppm.
Due to the water shortage, it's nearly impossible to get folks to drain 1/3 - 1/2 of their pool and refill. With the predicted high rainfall we're expecting, I was going to recommend that, when they expect a heavy rain, to drain 1-2" and let the rain refill it.
1st question: In some long ago chemistry class I seem to remember that draining before the rain would dilute the solution more than draining after the rain. If this is correct, does anyone have the formula that proves this?
Draining/refilling will take care of the problem but very slowly. I plan to use Bio Active enzymes to 'disassemble' the CYA molecule so the parts can off gas or be filtered out. This will have to wait until Spring since the enzyme won't work unless the temperature is >65.
2nd Question: I get mixed feedback from other pool pros - some say it works, others say no. Any 1st hand experience with this product?
Another step in lowering and maintaining the correct levels is to stop adding it. Most of the pools are using floating dispensers with dichlor tablets. The manufacturer tells me that they are 50% CYA so finding a different way to chlorinate is necessary.
- Calcium Hypochlorite has no CYA but increases Calcium Hardness
- Lithium Hypochlorite is at least twice the price
- Chlorine gas would work but I've decided not to do that
- Sodium Hypochlorite seems to be the way to go
3rd Question: Since I treat these pools weekly, should Sodium Hypochlorite keep the FC level up for a week? I think that if I bring it to 5 ppm, it should stay above 2 ppm by the time I return the following week. Feedback?
4th Question: Right now I include Sodium Hypochlorite in my monthly service charge. If I replace the dichlor with Sodium Hypochlorite, I will have to charge for that instead of the tablets. My customers are going to want to know if there is going to be a difference in price. I have records of how much dichlor they have used over the last year. If the tablets are 50% chlorine, that means a 25# pail contains 12.5# of chlorine. Sodium Hypochlorite is 12.5% chlorine so a gallon contains 16 fluid ounces of chlorine. I know there's a conversion formula here but I'm not sure what it is - anyone? Bottom line - I need to tell my customers if the conversion is going to cost more, less or stay the same
Clearwater Pool and Spa
Santa Cruz, CA