SLAMing instructions are good - understand them - use with confidence

TTWB

Member
Jul 14, 2019
8
Annapolis, MD
This year I opened the pool to insignificant algae and very clear water. Temp 50. I knew I needed to get my Free CL level up and in a previous post I got help on the "order" of all the various levels. Two days ago I got the levels where it is suggested that SLAMing would be most effective. (pH 7.1, CYA 30-50, TA 80 [I think]).

Point 1 - I really think getting these level within the recommended levels was important.

Next was to add CL. When and which type. All very well covered. Timing. most say due to sunlight shock before nigh time. But in reading the SLAM procedure the recommendation to check the CL not more frequently than once and hour but more than twice a day. I knew I was not obtaining Free CL. Knowing the role CYA plays in the effectiveness of the chlorine sanitizer is very important.

Point 2 - Using the CYA/chlorine chart is invaluable. The relationship is addressed in many areas and this simple guide is very important. Depending on my CYA (40-50 depending on my eyesight and hope) I need a SLAMing FC near between 10 and 16. Had I only gone to a "normal" of 3 I would have missed it.

Point 3- For me do this in the day! Timing. It is clear in the SLAMing process one should check the CL levels AND TAKE ACTION. I need to do this during the day! So yes there was sun light and there was that issue, but the CYA was at the right level and checking to take action is key.

After I placed in the PoolMath recommendation of 4 gallons liquid CL (12.5 % dated 21FEB2020 < yes know the date) I waited one hour and the FCL was 0.8 PPM. Procedures clear - add CL to get to the SLAMing level. Pool Math consistent (duh) add 4 gallons. I did - and immediately measured, yes before is was fully dispersed. FCL=4. I waited an hour and checked. FCL in excess of 10PPM which is what I expected and wanted.

Point 4 - Check CL and take action! Check frequently to the extent one thinks one might NOT be getting to the recommended CL level. Otherwise one has to start all over!

If one suspects, as I did, that there may be a problem in obtaining the recommend CL level, then heed the recommendation to have all the sanitizer and regents available. As the SLAMing process states one does really not know how much sanitizer will be necessary or how may testing of levels are necessary. So its a risk only if you buy too much; it is costly if you have to start all over.

Point 5 - Be prepared to observe and take action over a period of time - have regents and sanitizer available.

Well I need to check again... and get ready for the overnight test.

Great site; good transparent info. Almost all recommendation have very good basis in a number of professional and academic studies. The mentors who respond are knowledgeable and are quick to respond..

Freezing last night; pool water temp in the 50s, start swimming on Saturday here in Annapolis, MD (wet suit :) )

Stay safe -
 

TTWB

Member
Jul 14, 2019
8
Annapolis, MD
Success! Passed the overnight CL lost test.
Duration - 24 hours
Chemicals - 2 sets of 4 gals liquid CL (12.5%) separated by 1.5 hours for total of 8 gals
2 lbs of "Cal-Hypo" 73% (went to Cal-Hpo; didn't know how much more liquid CL I would need; didn't want to store any; used dry that I had.)
Tests 4: Initial, 1.5 hours later; 1.5 hours later, 3.5 hours later, 14 hours later in the morning