Re: First time SLAM - FC levels WAY high after first bleach
Ok, so the algae is coming back again, with algae spots on the pool floor and water getting a little cloudy. This time I know for sure that our FC has been high enough. According to the Chlorine/CYA chart on here, the target FC for 30CYA is 4. I've set my target at 6 and have checked the pool daily. Usually its around 4ppm when I check it in the late afternoon, so i add enough bleach to bring it back to 6.
A couple more details:
1. According to user "linen", he said I could probably run the pump even less than the 6 hrs I was running it last time when I started getting an algae issue. So after I SLAMed the last time (on Sept 4th-5th), I got the pool crystal clear and then turned the pump run time down to about 4.5 hrs/day.
2. This is a long story that you can read about on another thread, but I've had spring water from under our house dumping into the pool every several hrs, about 7 gallons each dump. I've just left it dumping most of the time, in order to just keep the level of the pool up from evaporation/backwashes, and not have to add any water with the hose. I have a duda-diesel filter (as suggested by another user) thats filtering the water from under the house, and there are a couple real small green algae spots on the filter bag (filter is hanging over side of pool but not actually in the water), so theres a chance a little algae is making it into the water from there, but it seems like keeping the FC at 6 should kill it enough to not have an algae issue right?
3. I've vacuumed about twice a week. It started as just vacuuming dirt/leaves, but since Thursday/Friday (about 1 week after the last SLAM) I've had to start vacuuming the algae spots up.
Anyone have any ideas why I keep having this algae issue? Both times I SLAMed I followed the process to make sure I met the 3 requirements for stopping the SLAM (water has to be crystal clear, pass the overnight OCLT test, and have CC less than .5 ppm). Both SLAMs we've done, after 2 nights of SLAMing, we passed the 3 tests. And this last SLAM, I set the target FC 2-3 ppm above the target FC shock level, just to be sure.
The only other thing I can think of is maybe the pump isnt running enough? But according to "linen" and the link about pump run time he posted (from pool school), apparently it really only needs to run enough to mix the chlorine in good, and any more than that is up to your preference on how clean you want the water to be from debris.
Another question - following BBB/SLAM methods meticulously like I have, how often would you expect to need to SLAM? And how long should a typical SLAM take?
I know I still have a lot to learn, but I really want a trouble free pool and want to figure out how to eliminate this algae issue