Getting ready for first SLAM

[QQQ]

My regular pool guys quit - so I figured this is a good time to figure things out myself. Meg and Dave from TFTestkits have been amazing and amazingly helpful. Anyway - my most recent tests:

FC 0
PH 7.2
CYA 40 or so - trying to get up to 60 or so
TA 120ish
70 degrees

I suspect I have some ammonia from CYA degradation as I had zero when I opened (I drained about half of the pool and then re-filled) and it was fairly high when I closed. Water is clear but I can't hold chlorine. Anyway... question(s)
1) Pool math says I should have 16 FC for shock. The "table" from SLAM says I should have about 24 FC for shock with a SWG pool. 24 seems CRAZY high. anyway - 16 or 24?
2) How much chlorine should have on hand ( I have the concentrated stuff and currently have 5 128 oz bottles)?

After putting chlorine in pool to raise to about 10 FC, by morning my FC was about .5 and combined chlorine is or was typically 1.5. It just went down VERY quickly.

3) Is it reasonably to start the SLAM in the evening and then cover the pool with my solar cover? Temp is lost quickly without the cover. I would start SLAM at about 6 PM, check a couple of times, add chlorine as appropriate, then cover at about 9:30, the un - cover and test in the AM and add as appropriate.

Thoughts? Photos at some point....

QQQ

 

[Azgirl71]

You go off of your current CYA level. Don't use the SWG during the SLAM. Remember it is a process that take time and patience.

As long as you take the cover off first thing in the morning and leave it off it should brok to have it on at night. It is better for the pool to breath though and that will help lower the CC also

 

[BoDarville]

Welcome to TFP!

If your CYA is holding, then any ammonia that may have been there before is gone or has largely been neutralized. Here's what I would do:

1. Proceed with the SLAM Process
2. Leave CYA at the current 40 ppm. It will be easier to maintain the required FC at 40 ppm CYA vs. 60 ppm CYA
3. Turn the SWG off - you will not use it during the SLAM. Use plain liquid bleach for chlorine until the SLAM is done
4. Your FC target is 16 ppm during the SLAM
5. I would keep the cover off during the SLAM to let CC's vent out.
6. Continue the SLAM until the criteria of Done are met.

Once the SLAM is done and FC drops below 10 ppm, check pH and adjust as needed. At this point, you can also add CYA to reach a total of 70 ppm. Wait for the CYA to fully dissolve (it'll take a while - perhaps a couple of days) and then turn on the SWG. In the meantime, use bleach for chlorination.

1) Pool math says I should have 16 FC for shock. The "table" from SLAM says I should have about 24 FC for shock with a SWG pool. 24 seems CRAZY high. anyway - 16 or 24?

The answer is 16 ppm for a CYA of 40. It appears you were reading PoolMath's recommended shock levels assuming a CYA of 40 , while reading the shock FC on the [FC/CYA][/FC/CYA] chart for a CYA of 60 (which is 24).

2) How much chlorine should have on hand ( I have the concentrated stuff and currently have 5 128 oz bottles)?

Hard to say - so many dependencies including bleach concentration and freshness -not to mention the pool variables. I would have more than you think you would need. Maybe see how much you go through on the first day or two of SLAMming and try to extrapolate out how much bleach you will need to finish the SLAM.

 

[QQQ]

Thank you! Should I just remove the sock with cya in it for now?

 

[BoDarville]

Yes. You can save it for reuse after the SLAM.

 

[QQQ]

Thank you BoDarville. I also have a Teledyne Laars Series One Heater. I hope it lasts a few more years. I suspect it is very old. Starting SLAM this evening.

 

[QQQ]

Start of Slam tonight. After two hours FC fell from 16 to 8. CC 4. CYA 40 ish. 70 degree pool. added another gal of chlorine to get up to 16. we will see what it after two hours and then again in the morning!

 

[Azgirl71]

Glad you got started. During the SLAM you only need to test FC and CC.

 

[QQQ]

8:45 - just over one hour. 5.5 fc 4 cc. cc is not moving and chlorine is getting used faster! More in a hour or so.

 

[Azgirl71]

Check the date on your bleach. If it is not 2015 stock then next time you add. Check 30 mins later to see if you are at target level. If you are not at target your bleach is weak and you will have to reduce the percentage to probably 6% and try it again.

 

[QQQ]

Dates are all either 15 or 16. Possibly testing error. I will be testing again in an hour and more will be known. Thanks for assistance!

 

[QQQ]

better! 10:20 - 8 fc 2.5 cc. tomorrow.... if pool makes it through the night!

 

[QQQ]

When I came back from adding chlorine, test turned pink again (it had sat for 10 min ) and took two drops to make it clear. So, 3.5 cc probably. Interesting.

 

[QQQ]

Re: Getting ready for first SLAM (Day 2)

Morning test - 5:30 AM. FC = 1 CC 2.5. Progress I think.

 

[Azgirl71]

Re: Getting ready for first SLAM (Day 2)

When I came back from adding chlorine, test turned pink again (it had sat for 10 min ) and took two drops to make it clear. So, 3.5 cc probably. Interesting.

You have to do the CC test right away after the FC test. Don't let it sit and then do the CC.

Morning test - 5:30 AM. FC = 1 CC 2.5. Progress I think.

Just keep at it.

 

[DaninFLA]

sounds like you got lots of algae eating your chlorine quick. if your shock level FC is 16, raise it to 20 when you add chlorine. then when it drops to 16 or below, bump it back up to 20. keep your FC at SLAM level as much as you can. adding some buffer will help you

 

[QQQ]

Thanks everyone! I don't have any visable algae - suspect amonia. but going through chlorine fast. However, there is some progress. Home from work to test and add shortly.

 

[Azgirl71]

If you have ammonia the chlorine will get eaten up quickly.

 

[QQQ]

11:30 - FC = 3 CC= 1. Close I hope.

 

[DaninFLA]

you are letting your FC drop too low. need to go a bit higher and/or add more chlorine more often