Pool numbers at pre-SLAM, Thursday afternoon (5-12-2016)
CC: 0.5 or less
Temp: 76 degrees
Thursday afternoon I decided to clean my filter cartridge because I noticed the pressure was up. It was completely green! Luckily, it easily washed off. I was surprised to see so much algae. We removed the light Monday so I guess there could have been some algae in the space but none was visually evident. I don't think that amount of algae could have grown in 4 days so it must have been there already. I haven't cleaned the filter since I bought it (60 days ago) because the pressure wasn't rising. My pool water was clear but on some days when I brushed I saw 'stuff' kicked up off the floor of the pool (especially if I had not brushed for 2 days). I chalked it up to dirt and pollen being washed from the screen enclosure into the pool from the rain and settling on the floor. I didn't see algae on the walls or on the floor of the pool. Because I'm paranoid about an algae attack, I check overnight consumption of FC once or twice a week and I had not seen any overnight consumption.
Obviously, given the condition of my filter (wish I had taken a picture, bright green covering all the folds of my relatively new cartridge) it was time to start a SLAM. I immediately added enough chlorine to raise my FC to 18 and then figured out a couple of hours later I was supposed to be at 24 (my CYA is 60). I also switched the pump to perpetual and brushed the entire pool. After purchasing my TF-100 kit a few months back, I purchased 16 oz of reagent (R-0871) and 4 oz of powder (R-0870) from Amazon because I was constantly testing the chlorine level as I got comfortable with the TFP method. As I started the SLAM, I had everything I needed to test, test, test!
Friday morning (6 am) I measured FC at 20.5 so it looked like 3-4 ppm had been consumed overnight. I brushed the pool and cleaned the filter again. There was a moderate green cast to the white cartridge which I hosed off. Over the day, I added chlorine multiple times and brushed the pool again. I cleaned the filter again in the evening. There was a very light green cast to some areas of the cartridge that easily hosed off. Ran the pump all night.
This morning (Saturday) I checked FC and none had been consumed overnight and CC was .5 or less and the water is really clear and sparkling. I cleaned the filter again and there was the faintest green in a couple areas of the cartridge.
So I guess I'm done?
After a day of hot FL sunshine (moderated by our screen enclosure, tighter weave on roof), the FC is still 22.5. It's going to take a week to get FC back to 7 or so!
Should I add acid even though I can't measure pH? My pH usually increases .1 to .2 per day.
In the pictures, you can easily see the drain that is 8' deep.