CYA Loss and Slamming

[mrcoop22]

First time poster here. I started using TFP last year when I found this site, ordered the TF-100 and began using the pool math App. I didn't seem to be holding chlorine and found out my CYA was low so worked on getting that raised up prior to closing down the pool last year. This year, I opened the pool and it looked great visually. My CYA was at 0 though. I bought Dry Stabilizer and put it in a sock in front of the return/in the skimmer as I worked on raising it up. I had to SLAM at one point and as I scrubbed the pool I found some white almost plastic like substance growing in the corners of my steps. I scrubbed everything by hand really well in the creases, around the lights etc... I passed the OCLT and CC were back to 0. I had the CYA up to 40 before we left on vacation in mid-June. During this time, I had been adding liquid chlorine to keep the levels where needed as I figured the stabilizer still needed to get higher. While we were away, my sister-in-law was watching the house and checking the pool for us. It started to get cloudy, so I had her bring it to SLAM level and it cleared up. She continued to add some chlorine, but not SLAM. When we got back home, I checked everything and my levels were:
FC 1.0
CC .5
PH 7.4
TA - 110
CYA - 0
No idea how my CYA got to 0 again. I bought some Liquid Stabilizer thinking that would get in the pool more quickly. I added it and the next day the pool was cloudy. I started to SLAM 6 days ago. By the next day, the pool had cleared up, but I continue to lose chlorine, and my CC's are generally .5 or 1. The pool is currently crystal clear and I have scrubbed, checked creases and nooks but don't see anything anywhere. I let up a little on the 3rd as we had people over, but was right back on the SLAM after that. Last night, my overnight chorine loss was 1.0. Here are some of the latest readings after each reading, I add liquid chlorine to raise back up to SLAM level (10) based on the Pool Math App.
7/4
2:00 p.m. FC = 2.0 CC = 0.5
7:52 p..m FC = 1.0 CC= 0.5
7/5
6:28 a.m. FC = 9.0. CC = 0.5
2:00 p.m. FC = 1.0 CC= 0.5
6:32 p.m FC = 5.0. CC = 0.5
10:19 p.m. FC = 5.0 CC = 1.0

Even though I only lost 1.0 from the 4th to 5th. overnight, I don't feel like I am done with these readings.... Should I be adding more CYA back in now or wait until I am done with the SLAM? I just don't want it to be gone again for whatever reason. Thanks for any help and advice.

 

[Texas Splash]

Welcome to TFP! During your Overnight Chlorine Loss Test, did you ensure the SWG was off? If not, it was an invalid tests. But if it was off, something is still wrong. You shouldn't be losing FC like that. In addition CYA shouldn't be falling. I would also confirm the following:
- Can you post a pic or two of your pool?
- Have you seen any signs of water loss? Done any leak testing at all?
- Did you remove the light during your SLAM Process?
- Do you have a main drain(s)? If so, did you remove the cover and inspect in there as well?

 

[mrcoop22]

Thank you! No. I did not have the SWG off. We do lose some water out of the pool but generally just most noticeable during hot dry weather when the pool is uncovered and/or there is a lot of swimming (or more so kids splashing). I started a leak test today, looking o.K. so far, but will continue and monitor this. I'll get into tomorrow and inspect the drains and the lights. The drains seem pretty straight forward. I have SR Smith Treo LED lights. Should I just be able to unscrew these from their housing? Sounds like this is ok to do while the water level is above the lights?

Below are some pictures I took of the pool today. Let me know if there is anything more specific you are looking for here.

Thanks again for the help!

 

[zea3]

You need to run an Overnight Chlorine Loss Test to make sure you are not losing your chlorine to the sun. Collect and test the first sample at dusk when the sun is off the pool, and collect and test the second sample at dawn before the sun is on the pool.
Does the pool have an auto-fill? If it does you may not notice a small leak but you will have a hard time keeping the pool balanced. You can change the settings in your pool app to share test results with TFP and that will help us troubleshoot your problem.

 

[mrcoop22]

Welcome to TFP! During your Overnight Chlorine Loss Test, did you ensure the SWG was off? If not, it was an invalid tests. But if it was off, something is still wrong. You shouldn't be losing FC like that. In addition CYA shouldn't be falling. I would also confirm the following:
- Can you post a pic or two of your pool?
- Have you seen any signs of water loss? Done any leak testing at all?
- Did you remove the light during your SLAM Process?
- Do you have a main drain(s)? If so, did you remove the cover and inspect in there as well?

I got in the pool this morning before work and removed the lights and took off the main drain covers. There was a little bit of black substance behind the lights which I scrubbed. When I opened the drain covers, I found a lot of grey-brown gelatinous substance in both drains that broke up when I tried to remove it. I'm sure this is probably at least a good part of my issue! Thanks for the suggestions.

You need to run an Overnight Chlorine Loss Test to make sure you are not losing your chlorine to the sun. Collect and test the first sample at dusk when the sun is off the pool, and collect and test the second sample at dawn before the sun is on the pool.
Does the pool have an auto-fill? If it does you may not notice a small leak but you will have a hard time keeping the pool balanced. You can change the settings in your pool app to share test results with TFP and that will help us troubleshoot your problem.

I'm running the OCLT tonight. I have the SWG off. No auto fill on our pool. I didn't see a difference in the bucket test yesterday. Today, we had 1.5 inches of rain. The water level was way up in the pool and in the bucket, but higher in the bucket. Not sure how accurate this is with all of the rain... I'm continuing to run this for now. I believe have the settings updated in my app to share. I've concentrated mostly on testing and adding chlorine lately. I was almost out of R-003 (gone through a lot testing chemicals and chlorine lately), so I have been doing the CC test sparingly. That order should be here tomorrow.

I'll post my OCLT results in the morning. Thanks for all of the help!

 

[mrcoop22]

OCLT = Last night FC = 10.5 and this morning FC = 8.5/CC = 0.5.

I'm continuing to SLAM. Hopeful that now it is just going to take a bit to kill off everything I found and scrubbed from their hiding places yesterday. Looking back, I think this is my smallest FC loss overnight so far and when I did the CC test, it was barely pink where generally I'm running between .5 and 1.0. Hopefully on the upswing here. I'll keep the SLAM going today and run another OCLT tonight.

Let me know if there is anything else I should be doing in the meantime...

Thanks!

 

[Texas Splash]

It's great you discovered those two trouble areas. I'm optimistic as well that you will get a handle on this FC loss now.