Marathon SLAM

swreeder70

Well-known member
Mar 15, 2016
93
Wimberley, TX
So I'm 11 days into my SLAM with no end in sight. Our pool stays open all year and is only 8 months old. Pool has always been clear, but we did hit zero FC during the winter due to some bad advice from our pool builder. We had always closed our pools before moving south to the new house, so I didn't question him at first. He claimed he treated it with PoolRX and I need not worry about CL level during the winter. After a few weeks thinking about this, I figured he was wrong and started to manually add CL...however I think it was all too late.

Anyhow this all lead to an unsuccessful SLAM a few weeks ago where everything seemed to go good, but two days after our CC shot up to 6.

So I went back into a full SLAM...11 days ago.

Going into the slam our numbers looked like this:
PH-7.4
TA-70
FC-3
CC-3
CYA-<30

I've been keeping the FC level between 15 and 20 very consistently adding 10% bleach from Walmart (onsale for $2.50 a bottle) It has been eating between 3-5 gallons per day depending on the amount of sunlight we are getting.

Two times I thought I was getting close where OCLT only dropped 2 at night with CC holding at zero only to have the CC come raging back into the 5-6 range several times. Today on day 11, I had the largest drop in FC going from 22 to 13 in 4 hours and the FC jumping up at the same time. The FC levels are swinging more the last few days rather than stabilizing.

With everything that is going on I'm 99% certain this pool has/had an ammonia problem.

So, what give here? Should I run a higher level of FC? I know with slamming it is to stay the course, but WOW, In 20 years of pool ownership I never experience anything like this.

I'm open to any advice here!
 
Once thing for sure... we've had some erratic weather. I would first go back to SLAM basics:
First, if you are REALLY worried about ammonia, do the 10-min drill:
- Increase FC to 10; check FC every 10 minutes to ensure it doesn't drop below 5. If it does, increase FC right away back to 10 and keep checking every 10 min until it holds between 5-10, then continue with the SLAM as noted below.

- Confirm that CYA. If it's below 30, add a little stabilizer to get ensure you are at 30. The sun is taking its toll. If you add stabilizer in 10 ppm increments, check about 24 hours later to see if that dot definitely goes away at 30.
- Keep the FC at 12 as much as possible
- The rest is on the SLAM page which I would review briefly each day as a reminder of things to do.

Hopefully with the K-2006 you are testing FC with the 10ml samples (multiply # of drops by 0.5) to save on reagents. As with any SLAM, in the early part it's very critical to watch the FC closely so it stays at 12. When it goes to 3 like it was recently, you've lost a lot of fighting power.


Hang in there.
 
Once thing for sure... we've had some erratic weather. I would first go back to SLAM basics:
First, if you are REALLY worried about ammonia, do the 10-min drill:
- Increase FC to 10; check FC every 10 minutes to ensure it doesn't drop below 5. If it does, increase FC right away back to 10 and keep checking every 10 min until it holds between 5-10, then continue with the SLAM as noted below.

- Confirm that CYA. If it's below 30, add a little stabilizer to get ensure you are at 30. The sun is taking its toll. If you add stabilizer in 10 ppm increments, check about 24 hours later to see if that dot definitely goes away at 30.
- Keep the FC at 12 as much as possible
- The rest is on the SLAM page which I would review briefly each day as a reminder of things to do.

Hopefully with the K-2006 you are testing FC with the 10ml samples (multiply # of drops by 0.5) to save on reagents. As with any SLAM, in the early part it's very critical to watch the FC closely so it stays at 12. When it goes to 3 like it was recently, you've lost a lot of fighting power.


Hang in there.

I've re-read that SLAM page every day hoping for a new clew to show up:D I'm on my third refill of the jumbo testing agents and just ordering another now as I am about 1/2 way through. My CYA tube only goes to 30 and I can barely see the DOT so I'm thinking it is closer to 25. I do have a bunch of pucks lying around that I can toss in the feeder to bring that CYA up.
 
Using pucks right now won't really hurt you, but they may take too long (to dissolve) to help you with the SLAM. If you're still seeing the dot at 30, it may be quite low which is why I suggested the 10 ppm addition right away. I know that CYA test is a tricky one, but try to use the last of our daylight to get a good reading to ensure you have adequate protection for the chlorine (FC).
 
Just to clarify since starting the SLAM my FC has never dropped below 15 except for one time today where it hit 13. I'm testing between every two - 4 hours for 11 days straight.

Oh and the speedstir paid for itself in the first three days of testing!!!
 
Last edited:
I think you meant "FC" never dropped ... :hammer: But yes, no doubt I could not imagine being without that speedstir. I once did OCLTs with an FC over 31. 72 drops gets old real fast. We'll watch your progress closely to see what other possibilities might be happening, or if there's anything else in the equipment we should consider.
 

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6:00am numbers:
FC 18
CC .5

Maybe the end is near!

One thing worth noting is when I started this SLAM it was the first time I started using the on-sale 10% WalMart pool chlorine. Just wondering if it is weak or I got a bad batch? I did think it looked awfully pale in color and didn't smell very strong when I opened the bottles (all 50 of them!)

Yesterday after starting back with the generic local 8.25% bleach my numbers were more stable during the day and overnight. Might be a coincidence. Anyone know how to decode the date codes on the WM bleach, I might have done that wrong.
 
6:00am numbers:
FC 18
CC .5

Maybe the end is near!

One thing worth noting is when I started this SLAM it was the first time I started using the on-sale 10% WalMart pool chlorine. Just wondering if it is weak or I got a bad batch? I did think it looked awfully pale in color and didn't smell very strong when I opened the bottles (all 50 of them!)

Yesterday after starting back with the generic local 8.25% bleach my numbers were more stable during the day and overnight. Might be a coincidence. Anyone know how to decode the date codes on the WM bleach, I might have done that wrong.

What was the datecode on them?
 
Ok, that is how I interpreted it as well. It was in my garage on the concrete floor in 70-75 degree temps...and at the rate I burned through it I don't think storage was an issue on my end. At walmart it was on an endcap, where it was before then, who knows...but they got a pile of it in the store I was buying it from.
 

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