Third time's the charm?

[berniedp]

Hi all,

after my 2 previous SLAMs over the past 2 months, I'm back at it... My pool was perfect with the SWG keeping the levels at the middle of the optimal range in the CYA/FC table (never dropped below 6.5 for a CYA of 80 - now at 70 after lots of rain).

Then, last Saturday afternoon, I put my suction cleaner in the pool (it was out since the last SLAM had been done and was soaked in a diluted chlorine mixture to sanitize) and by Sunday morning I noticed the water becoming opaque again. I started another SLAM on Monday and by Tuesday morning the water was crystal clear again. But I'm still loosing about 3 FC overnight. I have been cycling my waterfall twice a day (15 minutes each time at 8am and 6pm).

I'm at a total loss as to why this is happening again and again - I'm now brushing my pool multiple times a day thinking perhaps my robot kicked up some stuff that's been lingering on the bottom. We have also been fighting against centipedes (tiny ones, about an inch long) that keep ending up in the pool and get sucked out either via the skimmer or fall down to the bottom and I've been removing manually. Perhaps they and up in the filter and unless I clean that out more frequently (now doing it every two weeks) this keeps consuming chlorine?

I also noticed one part of the plaster on my pool has become like a tiny crater (I can feel it when I rub my toe on it) - my pool is about 20 years old (I have owned the house for 3 years now). Could it be that the plaster is so old / stained that it's causing this issue?

Any ideas? I know it's probably difficult to suggest but I've been through all the other steps multiple time and I'm at a loss.

 

[HermanTX]

It appears there are several things in play. First, before ending a SLAM you must past all 3 criteria.

• CC is 0.5 or lower
• AND your overnight chlorine loss test shows 1.0 ppm of loss or less
• AND pool water is crystal clear with no visible sign of algae (dead or alive) on floor and walls

It may be you never did complete a SLAM and the algae is just lingering. Then adding the pool cleaner could have introduced more algae.
I am not sure what is meant by cycling your water twice a day (15 mins each time). Is this putting your system in Spa mode? Your pump should run 24/7 while in SLAM Process

In your latest event it was stated that " I started another SLAM on Monday and by Tuesday morning the water was crystal clear again. But I'm still loosing about 3 FC overnight". Did you let your FC drift down below SLAM before meeting all 3 criteria? If so, I suggest you restart the SLAM and maintain the SLAM FC level for your CYA level for the duration until all criteria is achieved.

with 20 yr old plaster, it may be reaching end of life - so try to maintain your chemical balance but start saving to to a replaster in the coming years. The pot marks do not create algae, but it does give algae a place to take hold during brushing.

 

[berniedp]

Hi Herman - thanks for your help here

It may be you never did complete a SLAM and the algae is just lingering. Then adding the pool cleaner could have introduced more algae.

I passed all 3 requirements - I'm very positive as I continued for another day after my FC dropped 1ppm in the OCLT and the next day I lost only 0.5 - that's when I ended

I am not sure what is meant by cycling your water twice a day (15 mins each time). Is this putting your system in Spa mode? Your pump should run 24/7 while in SLAM Process

During the SLAM, my pump was running 24/7 and my waterfall valve is open all the time - with the 15 mins each I mean that I'm cycling the water in my waterfall twice a day since passing the previous SLAM. I believe that not having used the waterfall for a long time (> 2 years) and then switching it on caused the entire problem to begin with. I wrote this up here: Back to square 1 after previous SLAM

In your latest event it was stated that " I started another SLAM on Monday and by Tuesday morning the water was crystal clear again. But I'm still loosing about 3 FC overnight". Did you let your FC drift down below SLAM before meeting all 3 criteria? If so, I suggest you restart the SLAM and maintain the SLAM FC level for your CYA level for the duration until all criteria is achieved.

I have been adding chlorine multiple times a day since starting the process - measuring & adding morning, noon and later afternoon so I've not let it drift aside from what I lost each time between measurements.

 

[HermanTX]

Thanks for the clarifications. Have you cleaned around the lights? If you have nichless lights that is fine, but if not, then unscrew the light (usually a single screw at the top) and pull out the light and clean it and the niche. Sometimes algae lurks in there. Also, if you have any ladders or rails, clean around and under them with a soft brush with the SLAM water or make a small bucket of LC and water to clean them.

The bugs could be an issue as well but if you are at SLAM level then they won't survive long. Ensure you scoop them out.

Continue to run your waterfall twice a day while in SLAM mode. Also, I assume you do not have a spa so it is just a pool with waterfall.
Continue to clean your filter as that will capture all the dead algae.

 

[berniedp]

Thanks for the clarifications. Have you cleaned around the lights? If you have nichless lights that is fine, but if not, then unscrew the light (usually a single screw at the top) and pull out the light and clean it and the niche. Sometimes algae lurks in there. Also, if you have any ladders or rails, clean around and under them with a soft brush with the SLAM water or make a small bucket of LC and water to clean them.

The bugs could be an issue as well but if you are at SLAM level then they won't survive long. Ensure you scoop them out.

Continue to run your waterfall twice a day while in SLAM mode. Also, I assume you do not have a spa so it is just a pool with waterfall.
Continue to clean your filter as that will capture all the dead algae.

I did clean the inside of the niche last time - there wasn't anything visible in there - felt nothing slimy nor see anything discolored that could look like algae.
I keep fishing out the bugs - but they keep coming - my neighbors have the same issue
I'm running my waterfall full-time for now, it's indeed a feature, not linked to a spa.
Cleaned the filter this morning and didn't see much aside from dirt/dust but it was fairly clean - will do the same again in a day or two.

In the meantime, my other half is starting to question my "skills" - "The pool guys only came and checked the water once a week, why do you need to do all this?"
Explained the waterfall situation - the answer: "then stop using it, that should fix the problem" - it's not wrong and it's my last resort - kill the thing off...

 

[HermanTX]

Thanks for confirming light and other items. My suggestion is to keep the SLAM running and let us know when you pass all 3 criteria again. The last I saw was the OCLT was 3ppm. When done - keep FC on upper end of the range for your CYA.
After you run the waterfall for a couple of hours at SLAM level you can then reduce it to just a couple of times a day. The goal is to clean it real good with SLAM level FC then back off the running of that water feature because it is driving up the pH due to aeration.

 

[berniedp]

Hi @HermanTX - I finished my SLAM yesterday - <1 OCLT, 0 TC and water crystal clear (as it had been for a few days). I'm now letting my FC drift off and my 24h loss (yesterday 8am to today 8am) is about 3.
Once my FC reaches normal levels (I'm still at 20.5), I'll keep my FC on the upper range for my CYA.
Crossing my fingers I'm done for good now...
Thanks again for the help & mental support here - it does make all the difference at times like these and helps not to loose confidence!!!

 

[HermanTX]

Hi @HermanTX - I finished my SLAM yesterday - <1 OCLT, 0 TC and water crystal clear (as it had been for a few days). I'm now letting my FC drift off and my 24h loss (yesterday 8am to today 8am) is about 3.
Once my FC reaches normal levels (I'm still at 20.5), I'll keep my FC on the upper range for my CYA.
Crossing my fingers I'm done for good now...
Thanks again for the help & mental support here - it does make all the difference at times like these and helps not to loose confidence!!!

Great work and continue to test FC daily to monitor the FC level.

 

[berniedp]

Am testing each morning - keep your fingers crossed