I've been engaged in a SLAM since Friday June 17, and it shows no sign of ending.
I've made other posts, and some of you have been helping me out which I really appreciate. I'll try to consolidate all the relevant information here including the latest developments.
When I started the SLAM, there was no visible algae, and the water was crystal clear. The only reason for embarking on the SLAM was that I had just taken over maintenance of the pool and the free chlorine level was not holding.
My initial numbers on June 17, 2016 were:
For the rest of this post, I'll post FC and CC numbers only. I was told that the pH test is not accurate at elevated chlorine levels. I did test pH a couple times during the SLAM and it seemed to indicate around 7.0. (Slightly beyond the color scale.) TA and CH I did not test during the SLAM (and probably aren't relevant). CYA I tested on June 19 and June 25 and both times confirmed it was still at 30.
I have many measurements during the SLAM as I tried to keep the FC levels up, but I'm going to just give you the OCLT numbers.
Date Time FC CC 2016-06-17 23:00 9 1.5 2016-06-18 09:30 0.5 1 2016-06-18 21:45 10 1 2016-06-19 02:15 6 1 2016-06-20 01:00 11 1 2016-06-20 07:00 7.5 0.5 2016-06-20 22:45 15 1 2016-06-21 06:30 9.5 0.5 2016-06-21 23:15 8 0.5 2016-06-22 07:00 6 0.5 2016-06-22 22:30 9.5 0.5 2016-06-23 06:45 6.5 0.5 2016-06-23 21:15 9.5 0.5 2016-06-24 06:45 6 0 2016-06-24 22:00 15 1 2016-06-25 09:15 8.5 0.5 2016-06-25 22:30 13 0.5 2016-06-26 10:15 7.5 0.5 2016-06-26 23:15 13 0.5 2016-06-27 07:00 8 0.5
You can see that during the week I did not keep up the proper SLAM levels overnight b/c I knew I wasn't able to tend to the pool properly during the week, but during the weekend I embarked on it again wholeheartedly.
I did not have a brush when I started the SLAM, but I ordered one since then. But once again, there is no visible algae.
The inside of the skimmer looks clean. (Aside from the usual collection of leaves and bugs which I clean out daily.) At first, I thought the input well was filthy, but after I drained and cleaned it out, it turned out that it just looked bad b/c the well wall was black and made the water look dark. As I took the water out, it was mostly clear, and there was only a little sediment at the bottom. There are no ladders in the pool for algae to collect on, and the built in stairs look clean (but I have brushed them anyway).
One thing that got my hopes up for the cause was the in-pool light. I removed it on June 25 (so well into the SLAM), and when I did so, a bunch of debris flew out of the alcove -- pretty disgusting. I scooped out what I could and the rest I broke apart with the brush at the bottom of the pool so that eventually it should filter out.
Other than that, the only other thing I can think of is that the filter is dirty. I meant to clean it last weekend but did not get the chance. But my understanding that even if the filter is dirty, algae can't grow in there since there is no light. True or not?
So at this point, I've been sort of SLAMing for over a week. I know that I'll get told that I haven't been properly SLAMing since I did not keep SLAM levels up the entire time (during Monday through Friday of last week). That is true, and I fully admit that. But I have been keeping elevated levels (if not SLAM levels) so that it should at least have been prohibiting additional growth.
Since the beginning of the SLAM, I have added over 40 jugs of chlorine (1 gallon of either 8.25% or 10% bleach), so I'm kind of discouraged. It feels like the SLAM will never end. I think the advice people will give is to just keep at it. But doesn't it seem like things should have stabilized by now? My pool has looked great since the beginning of the SLAM. But clearly something is going on to cause the FC level to drop so much overnight. Is there a point at which I'm just going to stop? I don't want to if there's something consuming chlorine, but I feel like no progress is being made. I do feel like progress was being made in the beginning where a lot of CC was being produced and my chlorine demand was higher than it is now. But I don't feel like I'm making progress now.
Other than cleaning out the filter, what else can I do now? Are there any other "hidden" sources of algae or organics you can think of?
Thank you for all your help! You guys have been terrific in supporting me!