1240ppm....was 1500ppm in the spring but drained some. I’ve installed a whole-house water softener with a connection to my autofill line. My pool is now on a steady diet of zero CH fill water. I will be draining more once the weather cools and I recently acquired a higher discharge sub pump to do the differential draining that Marty described (pump in the deep end, fill water into the skimmer, no pumps running.
An RO system is useless on a pool for several reasons -
1. Unless you’re able to generate operating pressures above 100psi, RO is highly inefficient and the waste fraction will be very high (50% waste or more).
2. RO membranes are destroyed by chlorine so unless you pre treat the water going into it, the chlorine will quickly make a mess of the filter.
3. RO filters have very specific TDS requirement (salt + CH) and if you exceed them, you will lose efficiency.
4. RO membranes can foul very quickly with calcium scale so you either need to keep the TDS of the waste water in control (meaning you send a lot of water down the drain) OR you need to inject a scale inhibitor into the input line to keep calcium from scaling out.
Companies that sell RO services for pools are often less cost-effective than simply draining and refilling. Their main selling point is that you don’t have to drain the pool but rarely is their equipment any more efficient than a 25% waste fraction meaning that you will be running your hose into the pool while they are “filtering” you water. When you factor in their service charge plus the cost of the water you add to the pool as make-up, you’ve typically spent about twice what it would have cost you to simply drain and refill.
