Help with a SLAM

[Charliemike100]

Been trying to slam for about a week now. Started with ph at 7.2 but that's now up to 8.7. I must have added too much stabilizer as CYA was around 90 after 1st couple days. Pool is ~24k gallons. Been adding shock per pool math for a slam. Initially the calculator had me adding 8 to 10 gallons of 10% at a time. As I've vacuumed to waste and refilled cya has come down to around 30. Each time I checked FAC (usually 4 to 8 hrs after adding) FAC would be 0 (or nearly). I determined that maybe I wasn't checking often enough so I added 6 gallons last night and 1hr later FAC was 0. It doesn't seem like I'm ever hitting a shock point to 'level and maintain'. Is the pool math suggestion too low? Should I double up amounts and check more often? Since FAC is 0 (TAC is 3.7) should I try to reset ph back down to 7.2 before adding chlorine again? FWIW, as far as I can see (it's cloudy enough that I can't see the bottom in the deep end) there is no organic matter in the pool (I did remove tons of leaves and things the first few days). I have my poolbot running almost nonstop and while it did bring up a lot of sand and vegetation initially, it's now bringing up only the occasional small twig and very little sand)

Also, Filter is a sand filter but using filter balls. Pumps been running 24/7 since I started and backwash at least 2x a day.

 

[mknauss]

Welcome to the forum. Is that a current picture after all the chemicals you have added as described?

How are you testing your water chemistry?

 

[Charliemike100]

Welcome to the forum. Is that a current picture after all the chemicals you have added as described?

How are you testing your water chemistry?

Thank you. I just took that picture. I've not added any chemicals since last night. I'm testing with a Taylor DPD (couldn't get my hands on a FAS-DPD when I started though given the amount of time I should have had amazon deliver) and also since I don't trust things running it through an accublue spin disk to back up the findings from the Taylor kit.

 

[mknauss]

You need a FAS-DPD to perform the SLAM Process

Your yo yo of CYA levels is concerning.

With your FC falling to 0, I would suggest you add 10 ppm FC worth of liquid chlorine. Circulate the pool well and test FC again in 30 minutes.
Report the result.

Then prepare to add 5 ppm FC worth of liquid chlorine each day until you get your FAS-DPD test kit.

 

[Charliemike100]

Thanks for that. I should say that I mistyped. CYA did not go to 0.FAC did. CYA since I stopped vacuuming had stabilized around 30. Should I be concerned about the PH having gone back up? I'm going to see if I can get hands on a fas-dpd from a friend and will report back.

 

[mknauss]

pH test is invalid if FC above 10 ppm.

If pool is holding CYA, do not worry about the 10 ppm test process. Just add the 5 ppm FC per day until you have a proper test kit.

 

[Charliemike100]

So I continued adding 5ppm per day since my first post and today Got the fas-dpd test and So...... If I'm doing this right my FC = 65ppm (I'm guessing I probably shouldn't swim in it)

Water color is a significantly lighter shade of green and in the morning before I brush it is actually fairly clear in the shallow end.

 

[mknauss]

You used 10ml of water, one scoop of powder, and each drop of R0871 to clear was 0.5 ppm FC Thus you used 130 drops. Correct?

 

[Charliemike100]

You used 10ml of water, one scoop of powder, and each drop of R0871 to clear was 0.5 ppm FC Thus you used 130 drops. Correct?

All correct except that I used 2 scoops

 

[mknauss]

OK -- how did you add that much chlorine since Sunday adding 5 ppm FC per day?

 

[Charliemike100]

OK -- how did you add that much chlorine since Sunday adding 5 ppm FC per day?

I'm pretty sure that is the ridiculous amount that was already in there. I had been adding copious amounts of chlorine every day for a week by the time i posted because the dpd test kept reading 0

 

[Texas Splash]

130 drops? Can you post a new pic of the water?

 

[wireform]

Wasn't there something about over 50 drops.....

 

[Charliemike100]

130 drops? Can you post a new pic of the water?

 

[Texas Splash]

If you've had the FC level that high since Saturday, or even a couple days, with no visible changes, something seems odd. I'm not seeing a difference at all from your first pic. Of course you were waiting on the FAS-DPD to arrive, so prior attempts were a bit of guesswork, but now that you are able to test and maintain the proper FC level noted on the FC/CYA Levels, there should be visible changes soon. If not, something else is going on. Have you added any other chemicals to the water other than chlorine or acid?

As Marty noted earlier, an accurate CYA is extremely important for the SLAM Process to work properly. There were some significant changes to your CYA, so we need to ensure it's a close to accurate as possible. Please refer to the note below just to be sure you are doing it correctly.

CYA Testing:
Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Taylor recommends standing outside with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. If it helps, pour a little, look away, then look back and pour some more. Some people like to squirt enough solution to go line-by-line for a better feel. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, 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 the CYA reading. If you are still questioning your own results, have a friend or two do the same test 2-3 times. Share your results only after everyone is done to see if you came up with the same average results.