First opening, SLAM underway, but need some advice

[cucamelsmd15]

Hi all, long time lurker, first time poster. Thank you for the great resources here!

Lets get started, welcome to the swamp! This was taken about 2 hours AFTER I started vacuuming to waste. Yeah, it was bad.

Fast forward to later that day:

Looking better!

And as of this morning:

Now for a couple of questions:

First off, background on the pool is 16x32, approx 16000 gallons. Sand filter, vinyl liner.

Starting Chemistry:
FC: 0
pH: north of 8
CYA: 0
TA: 100
CH: 30

So, the previous owners who we purchased the house from last year LOVED the hockey puck chlorine tabs. I had CYA levels that were north of 300ppm last year, and I did a drain and fill a few times to try and replace prior to close, but since we are on a 675ft well that likes to put mud and silt in the water, I try not to pump off the well too much. That said, I managed to get the CYA levels to about half that prior to close with a plan to drain/fill when I opened this year. That was prior to discovering that CYA likes to convert to ammonia, explaining why the pH was so high. Step 1 was to get the pH down prior to starting the SLAM.

Saturday Chemistry:
FC: 16
CC: 10
pH: 6.8
CYA: 20-30
TA: 100
CH: 30

I noticed a big drop in the pH despite adding what I thought should be the right amount of sodium bisulfate. I went through 8 bottles of bleach and 8lbs of shock on Saturday/Sunday. I put dichlor shock in the pool mainly to put some chlorine in and to bring the CYA up.

Monday Chemistry:

FC: 8
CC: 25
pH: 6.8
CYA: 20-30
TA: 100
CH: 30

Heres what Im unsure about, and where my questions are:
1. Im noticing big swings in CC. I brought the FC back up this morning, and looking at the progression in the pics, I can see a color difference in the water, however, it is still very cloudy. Normal?
2. How reliable is the pH reading during a SLAM? Is this something I should try to adjust now, or wait until the SLAM is done?
3. My calcium hardness is pretty low, and I have calcium to add, should I do this during the SLAM or wait until after?
4. Lastly, in my shortsightedness, I realized that Im leaving town on Friday. What should I do about this if the SLAM isnt done by then?

 

[tim5055]

You Welcome to TFP!

1. Im noticing big swings in CC. very common, not to worry

I brought the FC back up this morning, and looking at the progression in the pics, I can see a color difference in the water, however, it is still very cloudy. Normal? Instead of a wide shot of your progression photos, take them looking down at something, like strep. You can then see the progression clearer.

2. How reliable is the pH reading during a SLAM? Is this something I should try to adjust now, or wait until the SLAM is done?pH test reads high when FC above 10. Keep going with the SLAM

3. My calcium hardness is pretty low, and I have calcium to add, should I do this during the SLAM or wait until after? Wait

4. Lastly, in my shortsightedness, I realized that Im leaving town on Friday. What should I do about this if the SLAM isnt done by thenot to be a pessimist, but it probably won't be. Unless you can find someone to add bleach a couple of times a day not much to do but stop and re start when you return. There is no magic trick

 

[cucamelsmd15]

I think Ive run into a potential issue.

Monday evening Chemistry:

FC: 4
CC: 20

Decided to take pictures of the steps to show clarity, they are below.

Tuesday morning chemistry:

FC: 4
CC: 16

Added 2 bottles of 10% chlorine. Unfortunately, its raining today. My main issue is that from yesterday morning to today, Im not seeing any differences in the water.

And this morning:

Wider shot from yesterday:

 

[Texas Splash]

That HUGE flip-flop of FC and CC is a good indication you have ammonia in the water. Please do the following:
1. Begin a SLAM and dose FC up to SLAM level. If your CYA test is showing as zero (perhaps already converted to ammonia), use a SLAM/Shock FC of 10. Do not add additional CYA at this point.
2. Retest FC at 10-minute intervals.
a. If FC loss is greater than 50%, add FC to bring back up to SLAM level and continue retesting FC @ 10-minute intervals.
b. IF FC loss is 50% or less, add FC to bring back up to SLAM level. Go to Step 3.
3. If CYA is below 30 ppm, add enough CYA to bring level up to 30 ppm.
4. Continue SLAM as directed in the SLAM article until the SLAM Criteria of Done are met. Test as directed in the SLAM article - no longer need to test FC at 10 minute increments at this point.

 

[cucamelsmd15]

Ammonia would make sense since I had a high level of CYA prior to close and had none at opening.

Guess Ill make another Walmart run tonight for more chlorine.

Question: When retesting at 10 minute intervals after adding, should I be brushing or otherwise agitating the water in between, or will it disperse enough? I always add liquid chlorine in front of the jets as a matter of habit anyway...

 

[Texas Splash]

Definitely have the pump running, and it won't hurt to manually move water around if you have a minute or two, but simply staying on it every 10-min to add bleach is the biggest thing at the moment.

 

[kimkats]

Make sure the pump is on and you can brush if you want to make sure it is mixed in good.

It will be a fight in the beginning but after a while and lots of bleach you will see the FC demand dropping.

Do NOT add any CYA as that is "food" for the ammonia.

Kim:cat:

 

[MarianParoo]

Would you please retest the pH sometime too? Since pH tests high at high FC levels, I am concerned that your pH might be very low.

 

[cucamelsmd15]

Yep, I will retest pH this evening. Im also concerned about it being low since chlorine SHOULD skew it high.

 

[cucamelsmd15]

Retested pH and it took 15 drops of base demand. Ive added some pH up, but now Im extremely concerned about this. Based on my back of the napkin math, that would mean pH at or around 5, and I didnt add THAT much ph Down...

Second thing I did was test CYA and FC/CC.

FC: 0.5
CC 4
CYA 35

CYA has essentially remain unchanged. Pool Calculator says 289oz of 10% to bring back up to shock level, which Ill go add now and proceed to recheck within the hour to see if I need to add more. But given the CYA is still present, Im wondering if I do in fact have an ammonia issue. Advice?

 

[cucamelsmd15]

20 mins after a bleach and scrub, FC was back to 3 and CC was 20. Guess that answers that question...

 

[MarianParoo]

Well let's see what your new numbers are. I am glad to see that the CC is way down. I am hopeful you have broken through on the CC issue.
And I don't think you have ammonia if your CYA is holding.

- - - Updated - - -

Cross-post

 

[MarianParoo]

Since your CYA is holding at 35, (say 40), take your goal up to 16ppm for your shock level.

- - - Updated - - -

Assuming of course that you were still using 10.

 

[cucamelsmd15]

Think I broke the cycle. After 40 minutes, 6 bottles of 10% bleach, FC was 20, and CC didnt even register. I didnt add anything else and will retest in 20 minutes or so.

 

[Texas Splash]

 

[BuckeyeChris]

as an aside, is there ever a concern that combining all that chlorine with ammonia will produce vapors that could do damage to someone out there brushing the pool?

 

[Texas Splash]

Not that I'm aware of BC. It's usually outdoors anyways, so I'm not sure that even if there was a potential for concern that it would accumulate. But that question does go slightly beyond my brain cells. :joker:

 

[MarianParoo]

Yay, cuca! You go!

 

[cucamelsmd15]

Checked again just now, FC seems to be holding steady. Ill check it again before bed and adjust if needed, but hopefully it will remain high until the morning.

 

[MarianParoo]

Yay! Just keep testing, adding, and repeating that process as often as you are able. (Wait an hour or more after additions before retesting). You've got this now!