Help with first SLAM

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Another update, in case anyone was wondering:

The week was busy so I have only been able to check first thing in the morning, at lunch a couple days and then 1-2 times in the evening. The water is definitely as clear as it has been in weeks, but I still feel like it is somewhat cloudy. I embarrassed to say that as a new pool owner and after going weeks with this problem I'm not sure I know what cyrstal clear looks like! :oops:

CC has been 0.5 or less all week. I'm consistently losing 2-3ppm overnight though. I just added it all up and I have used just over 43 gallons of mostly 12.5% chlorine in the 7 days I've been slamming. I'm planning on vacuuming, brushing and trying to check every 1-2 hours over the next 3 days and then I'll see where it is on Monday morning.
 
If you have debris that sinks to the floor, let it settle then vacuum it to waste and you will save time and FC. You said you have two lights, put on your old swim suit and open up the lights, clean then out. Chlorine is effective but a sponge is faster. The s pool is safe to swim in when clear enough to see the floor and the FC. Is at or below shock levels.
 
OK. I won't bother checking every 1-2 hours. I'm targeting 20ppm.

I've been too busy to vacuum this week and my automatic pool cleaner is busted so vacuuming is my first priority this afternoon. I'll take a look at the lights as well. Thanks for the tips.
 
D&Jplus7 said:
If I'm consistently reading CC of 0.5 or less, what is causing my FC to drop at night? CC above 0.5 indicates the FC is breaking down something, correct? So if I'm getting low readings the FC shouldn't be used up.
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In your case at night the FC in addition to breaking down the algae is also breaking down the CC fast enough that you don't get measurable CC. If at some point you let your FC get low while there are still organics in the pool, then the CC might show up. It is not uncommon at all to have an algae outbreak and to have very little measurable CC during the whole SLAM process. CC is a good indicator of needing to SLAM, but the reverse is not always true (i.e. having no CC being a good indicator of not having to SLAM).
 
I've met two of the three tests now. I vacuumed and instead of just backwashing decided to completely clean the filter and add new DE. Sunday morning the water was as crystal clear as I have seen it. So I have clear water and less than 0.5 CC, but still lost 3 ppm overnight when I checked this morning. The past couple mornings there is still sediment & film deposited on the floor. The only thing I haven't had a chance to do is check the lights so I'm going to try to get them checked early this week.
 
I took some time and pulled the two lights out yesterday evening. Nothing of any significance, just some sediment that I easily scrubbed off. I scrubbed them down with bleach to be safe and got them reinstalled.

So I continue to have crystal clear water and CC less than 0.5. Yet again this morning the FC decreased by about 3ppm. Is it just a matter of persevering or is there something else I could be missing? I'm closing in on 50 gallons of mostly 12.5% chlorine and 11 days of SLAMing.
 
I would raise the FC to 25-29 range for 24 hours to give it an extra push. Has the FC been dropping below 20 ppm during this slam process? If so, that will extend the time that it will take for the pool to be rid of the organics. You want to keep it at or slightly above 20 at all times and make sure you are brushing every day.
 
From the advice of other as well as from the pool school articles, I have not been testing ever hour. The first 3 days I was testing every 1-2 hours and keeping it up at 20ppm. All of last week I checked in the morning and then came home from work at lunch and then checked twice in the evening. That is the pattern I've typically been following for most days except for those first few. The majority of the time the FC is dropping to between 15 - 17. I did realize late yesterday that I had forgotten to brush for the last couple days. I'll raise it up to around 25 this evening and brush it.

Did I misunderstand the SLAM process? Should I have been raising it up to 25 or above so that it never went below the target of 20? I was always adding enough to get it up to 20, but then obviously it would decrease.
 

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It all depends on how quickly the FC was being consumed. If you targeted 25 and it was only reading 20 by the time you tested, then you should target 27 the next time. What you want is for the FC to be at or slightly above 20 when you test. If the FC reads 20 then I would add 2 or 3 more points worth of chlorine to make sure it doesn't drop below 20.

After awhile you will get a good idea how much chlorine is being consumed and you can dose accordingly to your schedule. If you can't test as often then you will want to target a little higher than someone who can test every hour.
 
Finally!! :party: :whoot:

My OCLT, the last piece of the puzzle, finally passed this morning. The water looks great and I'm just so relieved to be past this and looking forward to maintaining the pool myself and never (hopefully) having to deal with something as severe as this again. Thanks to all for the help.

So just a couple questions moving forward. Am I correct that the CYA may not be accurate to measure until the chlorine levels go down? Should I wait a few days to test? My PH was a bit on the low side when I started so I want to test that as soon as possible. Do I need to wait for that at all as well?
 
The only time you need to wait to test CYA is if you are adding dry CYA to the pool. It takes up to 7 days to dissolve and register on the test. Wait for the FC to drop and test the pH.
 
OK, just one follow up I thought might be better to add to this post instead of creating another. I tested everything over the weekend after finishing the SLAM and found my CYA to be around 90. If you read back to the beginning of my SLAM you'll see that I started with 50. Does the SLAM process raise CYA or is it more likley that maybe I misread the CYA in the beginning? I know CYA is the most subjective test and I do struggle with whether my eyes are deceiving me as to whether I can see that black dot or not, but it seems strange that I would mess the test up that much from beginning to end. Now I'm faced with having to drain almost 50% of my pool.
 
Funny but my CYA dropped from 80 to 50 during my SLAM. I attributed it to the murkiness from the algae...at least partly. I'm no expert but I wouldn't think you'd need to drain for a CYA of 90 unless maybe you were just starring a SLAM. But I'll defer to the experts on that.

Sent from my DROID RAZR using Tapatalk 2
 
CYA does not go up or down during the SLAM unless you manipulate it by adding CYA or adding fresh water.

Murky water has little to no affect on the CYA test.

While those variations are quite large, testing error is about the best explanation....I can think of nothing else.

CYA of 90 is tough to manage in a manually chlorinated pool....your FC must be between 7-10 ppm.

You can choose to keep it there if you dedicate yourself to keeping FC at that level and then readjust in the Spring......only because the swim season is now short.

Don't try to manage the pool at CYA 90 for an entire season.
 
Two thoughts on you cya rise...
1. Did you do the cya test in the same lighting conditions. The test should be done when the sun is out and at your back.
2. By chance did you use any trichlor or dichor during the SLAM (it doesn't seem you did but I thought I would ask)?
 
I did not use any dichlor or trichlor during the SLAM. I honestly can't remember if I tested it correctly before the SLAM started. I know I did it correct over this past weekend. I'm still kind of stumped, but I guess I must have messed up the initial test. Thanks for the feedback.
 

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