We inherited a pool with our new house in August. I've had trouble with algae, water will be crystal clear for awhile, I'll brush sides and bottom and see a green film arise. Pool then turns cloudy green, and I'll SLAM again. I've done this three times. Granted, I may be messing up the SLAM process, but I will meet all criteria for couple days in a row before I quit.
The pool does need to be resurfaced so I thought rough areas on floor and walls was giving algae place to hide and make hard to kill. After my 12K-13K resurface estimate, I decided I wanted to look at filter. I did find out from guy who took care of pool for former owner that he thinks they changed changed sand 5-6 years ago.
This past weekend, we opened filter. The freeboard was 15 inches and the manual for our model (Triton TR-60) specifies a freeboard of 10.5 inches. So that could have been some of our problems, sand loss over time. The question I have is about the sand we removed, it was greenish tint. I have a picture below of clean sand, and the sand removed. Has anyone ever seen sand like this? I was told by the former pool guy that the owners used a mineral pack system. I looked that up and it says the minerals contain copper. I'm am not doing the mineral system. The feeder is still in place but empty. I'm using the BBB method.
Would mineral packs cause the green sand?
Could my algae issue be caused by the low sand level. Was the green sand a problem?
I'm currently on Day 4 of SLAM (Target FC 22 with CyA of 55). My OCLT has been zero for 3 days. The CC is zero. The water is now a white cloudy vs green cloudy and drain is visible. I still see a greenish dust stirred up when I brush however, it is more whitish than green now. I am going to continue SLAM until I don't see the green when brushing.
The filter pressure increased 5 psig during the first 24 hrs of SLAM. I backwashed. It has increased 1 psig in 2 days. I'm considering adding some DE. Should this only be done when I need some help filtering, such as during SLAM. Or can this method be used on a normal basis, after every backwash?
Do I need to vacuum when done if I don't see any dead algae on bottom. I'm not sure if the white powdery stuff I disturb while brushing is dead algae or pool surface coming off.