Am I doing something wrong

[ScottCh]

Let me start by thanking the experts that contribute their time to this forum. I'm hoping one day to join those ranks. Now on to my delimma. In April the pool finally reached temeratures warm enough to think about opening. The water had stayed beautiful throughout the winter. I began the process of getting my CYA up as it was still low from putting up the pool last summer. About this time pollen season set in and I noticed my pool was starting to tint green rather than yellow and I was starting to get clumps of what i thought was sediment on the pool floor but in hindsight i now realize it was probably dead algae. Then i started to notice green at the bottom of the pool wall so I began the SLAM process. After about 4 days the water had returned to clear, I got no overnight chlorine loss and was registering no CC's. So i stopped the process and resumed raising CYA. We had been using the pool for about 3 weeks when I noticed the clumps of stuff on the pool floor again. We had several rains during the time we had been using the pool and my male dog tends to like drinking from the pool instead of his water bowl and gets his dirty paws all over the side of the pool so i didn't think anything about the stuff on the bottom of the pool, again thinking it was just dirt. So i vacuumed the pool and we kept swimming. About 3 days later I noticed the green climbing up the pool walls again. So I am now in the process of SLAM'ing yet again. What I'm wondering is if maybe I'm doing something wrong in my testing. I have the tf100 test kit and a speed stir. During SLAM i use the recommended chlorine drop test along with testing for CC's. I fill the tube to the 10ml mark and do both test on that 10ml of water using the speed stir for both test. The odd thing is I have never registered any CC's, back in April or now. Am I doing something wrong? My water is crystal clear and I registered no overnight chlorine loss but I'm afraid to stop SLAM'ing due to my last results. Below are this morning's readings. Any advice would be greatly appreciated.


FC 20
PH 7.7
TA 70
CYA 50
CH 125
CC <.5 ??

 

[Azgirl71]

I would just follow the Slam process a couple of days. My guess is that your FC dropped during that 3 weeks and you got Alger again.

 

[AimeeH]

It sounds like you are doing everything right but......possibly letting FC drop too low while not slamming?

I have had repeat issues this year then my daughter pointed out to me algae in small cracks in the steps (not flawed but the way they are made and attached to the frame) had algae. Places my pool brush would never reach. I got in last weekend and brushed every crack I could find with a hand brush. Found algae behind the front frames of the skimmers too. Finally passed OCLT 4 days after that.

 

[Divin Dave]

My thinking is along the same as AimeeH. Somewhere along the line the FC is getting too low for too long a periord of time.

Go ahead and slam, and then then maintain FC relative to the CYA level.
Pool School - Chlorine / CYA Chart