Hi all, this is our first summer with our new pool (built in October); it is hot and very humid here in TX. I have been a diligent follower of the methods here since we built the pool.
Last week, we came back from a five-day trip and had some heavy cloudiness in the pool; brushing revealed some green-ish/yellow-ish bubbles on the surface, so I SLAMed. During the SLAM, I brushed and backwashed. Everything cleared up in two days and I passed the tests. Current numbers are (via TF100):
FC (FAS-DPD): 3
CC: (FAS-DPD): 0.5 or less (just very barely turns pink when starting the CC test)
Two things struck me as odd after the SLAM:
1. The pH has dropped precipitously, and seems to want to stay there. Previously, I would add about half a jug (the pH in our pool falls constantly, which I understand is common with salt pools) to get from low pH (7.2-ish) up to 7.6-7.8 range. Now, half a jug does almost nothing. I've added half a jug the last two days, and seen no movement up from 6.8. I am getting ready to add quite a bit today, but is this normal to see the pH suddenly become very stubborn after a SLAM?
2. My TA has dropped a lot. For the entire 10 or so months that the pool has been in operation, it's been stuck in the 110-120 range (last few readings have been 110). I did some aeration about a month ago after reading here (somewhere) that SWGs were more efficient at a lower TA, but it never went below 110. Now it's dropped a lot, and I'm wondering if it's connected to the sudden stubbornness of the pH.
Finally, I'm wondering if anyone has much experience with SWG percentage/pump runtimes in hot climates. Pool is in full sun and is now pretty warm (~87 degrees). It seems like a have to run the SWG at 60-70% to keep up. Pump is running 9 hrs per day at 1500 rpm. Any suggestions on runtime or best practices would be greatly appreciated. Thanks!