First SLAM Questions

tmartini27

Member
Jul 27, 2018
16
DALLAS, TX
Hi All,
This is my first try at slamming our pool. We have had on and off problems with yellow algae for the past 2-3 summers. So we got the good kit, made the switch and started the slam 7 days ago. We're still losing 2-3 ppm at night and I'm testing and adjusting the water 3-4 times per day. Brushing daily. Hasn't needed vaccumed in days. Water looks clear. DE filter pressure up since the start but still within normal range. No sign of algae but still using a good 2-3 bottles of 8% bleach a day. Most recent test results are from this morning:
TC = 27
CC = 0.5
PH = 7.6
TA = 120
Calcium = 150
CYA = 60 (rounded up as it was between 50-60 on test)
I rebalanced ph and TA last night. CYA reading is same as at start of slam.

My questions are should I be adding chlorine to try to maintain TC at or above 24 or should I wait until it dips below and then bring it back up? Do you normally see a steady decrease in bleach usage or does it just suddently stop devouring it? We also have an attached spa and booster pump powered vacuum. Any special considerations there? Thanks for your help. I'm trying to be patient but man it's killing my kids that they can't get in the pool!
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
With a CYA of 60, maintaining an FC of 24 is ideal. Of course it will drop a bit when you leave for work or something, but you bump it back up as soon as you can. Going much over is generally wasted more to the sun than gaining any benefits against the algae. Did you pull any large lights to clean behind the niche if applicable? Ladders, steps, rails..... anything else that could harbor algae?

You CAN still swim. With a CYA of 60, as long as you don't go over an FC of 24 it's safe. [FC/CYA][/FC/CYA]
 

Jhsparky82

Bronze Supporter
May 31, 2018
90
Appleton WI
Remember algae are microscopic. Just because you see clear water doesn't mean they're gone. That's why we do the OCLT. I've been in your shoes, and it's tempting to say good enough. But it'll all be worth it in the end. My inaugural SLAM took over 3 weeks, but I learned a valuable lesson: an ounce of prevention is worth a pound (or in this case, gallons and gallons) of cure. Stay the course, you'll be well rewarded
 

tmartini27

Member
Jul 27, 2018
16
DALLAS, TX
With a CYA of 60, maintaining an FC of 24 is ideal. Of course it will drop a bit when you leave for work or something, but you bump it back up as soon as you can. Going much over is generally wasted more to the sun than gaining any benefits against the algae. Did you pull any large lights to clean behind the niche if applicable? Ladders, steps, rails..... anything else that could harbor algae?

You CAN still swim. With a CYA of 60, as long as you don't go over an FC of 24 it's safe. [FC/CYA][/FC/CYA]

Yes, we pulled the lights before the slam and again 2 days ago. The only thing we haven't taken apart is the vacuum and I was considering doing that this weekend. It lives in the water though so I wasn't sure if the FC would kill everything. Will swimming effect the length of the slam? Thanks!

- - - Updated - - -

We also scrubbed out the skimmers 2 days ago.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Swimming won't disrupt the SLAM at all. In fact in may help with the additional movement, circulation, and if someone wants to while they're in there .... brushing. You may need to look at the vacuum just to ensure it's clean. If you've exhausted everything else, have good circulation, and are following all the instructions on the SLAM Process page, I wonder if your CYA may actually be slightly higher? If so, then of course your FC level would need to be higher, but only if your K-2006 CYA testing confirmed it as such.
CYA Testing:
Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Use the mixing bottle to gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Recommend standing outside with your back to the sun and the view tube in the shade of your body at waist level. Then, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. To help the eyes and prevent staring at the dot, some people find it better to pour & view in stages. Pour some solution into the viewing tube, look away, then look back again for the dot. Repeat as necessary until you feel the dot is gone. After the first CYA test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, gently shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate your own CYA reading. Finally, if you still doubt your own reading, have a friend do the test with you and compare results.
- - - Updated - - -

Oh, and just to make sure ..... do you have a main drain? Those have been known to trap debris under the cover.
 

Glofton

Well-known member
Jul 3, 2018
62
Loganville Ga
Just completed my first SLAM a few days ago. Make sure you have an accuarte CYA reading. I didnt test my CYA outside in the sun which affected my results and therefore I was not SLAMing at the correct FC level causing a longer SLAM. Also, my pool consumed bleach like crazy the entire SLAM then all the sudden it stopped. My overnight FC losses were 6-7ppm everynight, then suddenly it stopped losing. I continued for one extra day just to be sure. My SLAM lasted about 13 days and used about 100 jugs of bleach. My point is, stick with it, I know its frustrating but it will work if you stick with the plan. Oh, dont forget to brush like crazy EVERY single day!
 

tmartini27

Member
Jul 27, 2018
16
DALLAS, TX
Thanks all for the suggestions. I'll check the CYA again tomorrow. I did it outside last time but it was slightly different from the protocol you listed. Fingers crossed we're getting close!
 

tmartini27

Member
Jul 27, 2018
16
DALLAS, TX
Woke up this morning and only lost 1ppm! Officially passed all parameters of slam. So today we take it up to mustard algae shock levels and then have a clean and clear pool! Thanks for the help all.