FC dropping

Mike1162

Silver Supporter
Jun 13, 2015
719
N Tonawanda, NY
I'm pleasantly surprised how good mine looked. I didn't do anything to the light or drain & just waved my hand around the niche to remove some debris that was in there. The 15lb dumbbell worked well.
 

Thegatorvault

Active member
Jun 10, 2018
41
Tampa FL
Starting day 7......
Performed by OCLT last night:

10p - 31ppm
6:45a - 30ppm

You may remember that I was going to take Marty's advice and let the FC drift down to about 20ppm for swimming and then do my OCLT at this level. Well, I had my wife pick up some 'bleach' at Target to clean my vial and sample cup. Cleaned them both when she got home around 2 and just let the 'bleach' evaporate in both. Before folks started to arrive, I tested my FC at around 5:30p. Threw in a heaping scoop of 0870, turned pink for a second and then went clear. Threw in another scoop, turned pink for a second and then white clear. Zero FC! I must have really ****** off the algae gods and my battle just became a war! I panicked because I only had about 1.5gal of the 10.5 CL left since I figured that would get me through my OCLT and if needed I could get more in the AM. Now, that would only get my FC to 11 but good enough to let the kids go swimming, so I put it in.

Well the kids only swam for about 30min sometime around 8p. At 10, I checked my FC and it was back at 31ppm. So, trying to figure out what the **** happened, the only thing different with that test was my 'bleach' cleaning. I didn't really pay attention to what it was before I used it to clean my cup/vial but it was a Target brand 'bleach' and had absolutely nothing on the label that gave any indication what was in it. I guess it must have had some additive that mucked up my test. So my FC level at 5:30p must have been really close to 20ppm when I added the last bit of CL. This mishap just delayed my 20ppm OCLT by a day so I'll try again tonight.

Live and learn!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
32,525
Laughlin, NV
You passed the OCLT at 31 ppm FC! Still do one at a lesser FC tonight.

Also, the test that messed up is most likely due to the bleach being left in the vial. Rinsing it out was necessary. High FC will wash out the R0870 powder color.
 

Thegatorvault

Active member
Jun 10, 2018
41
Tampa FL
You passed the OCLT at 31 ppm FC! Still do one at a lesser FC tonight.

Also, the test that messed up is most likely due to the bleach being left in the vial. Rinsing it out was necessary. High FC will wash out the R0870 powder color.
Ah....ok. I was afraid washing out the cup and vial with tap water (what I normally use) might possibly affect things as well, so that is why I didn't flush them out. I guess technically you would want to flush the bleach out with DI water to be completely sure you had zero constituents left.

Thanks again Marty. Your expertise and guidance is greatly appreciated!
 
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Thegatorvault

Active member
Jun 10, 2018
41
Tampa FL
Starting day 8......
10:15p - 24ppm FC
6:30a - 24ppm FC
6:30a - .25ppm CC

Success and my SLAM is officially over! It was a bit cloudy/overcast here yesterday, so my FC level only dropped 6ppm the whole day. In my mind, that was a sign of good things to come.

Still not sure exactly what was in my pool since I never saw any signs of algae anywhere, except in my overflow piping. On the overflow pipe, I am planning to cobble something together so that the end has a cover (I'll try to post some pics). I don't know if that will deter the algae growth any since the end won't be in direct sunlight, but it should prevent rain from causing any back-flow into the pool. That and of course I plan to pour some bleach in there from time to time. I still don't know if that was the root cause, but whatever 'it' was, the SLAM took care of it.

As far as the SLAM itself, it was really a great learning experience although a little bit time consuming (glad it happened during COVID!). Because I had never done one before, I think the toughest part of it is the mental aspect. As a SLAM virgin, you personally are in unknown waters (no pun intended). You know something is wrong but you don't know exactly what so there is a certain level of pool panic. Of course once people find out your pool is having a problem, it seems everyone is an expert and knows how to fix it; your builder, the pool store, your neighbor, your wife, etc. Most of this advice deviates from what you have been doing and what you are planning to do. It can be a lot of noise and make you question if you should even be taking care of your pool in the first place. Then you have this forum.....pool school, pool math, articles/instructions, great members, and real experts. So the TFP kool-aid you have been drinking for years is now really being put to the test during your first SLAM. Having been through it, all I can say is have faith and trust the process!
 
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Thegatorvault

Active member
Jun 10, 2018
41
Tampa FL
Small update......my FC level has been slowly coming down. I did a full log two days ago....results:

FC - 7.5ppm
pH - 7.5
TA - 70
CH - 275
CYA - 60-70
Salt - 3800
Temp - 91
CIS - -0.39

My SWG has been at 80% and running for 11hrs per day since I finished my SLAM. I purchased 8lbs of calcium chloride to bring my CH level up. To be honest, this was a head scratcher since it has been pretty steady at 325 for a year and half (dropped from 350 initially after the build). So, I tested FC and CH again before I added the calcium chloride: FC yesterday was 5.5 and CH was 275. I added all 8lbs of the calcium chloride by following instructions i.e. mixing lb at a time in 5 gallon bucket and pouring in, brushing the pool each time afterward. I also added a little bit of Muriatic Acid to lower my pH since I shoot for 7.2 and let it drift up.

Checked FC and CH today at 11a. FC was 2.5 (CC was 0) and CH was back up to 325. I felt the FC drop was more than I expected, so I just adjusted my SWG up to 90% for 11hrs afterward. I guess my question is.....does the calcium chloride affect FC at all? I find it strange that my CH had dropped after my SLAM and stranger that bringing the CH back up to 325 may have had a negative affect on the FC. I saw another post on this but the response was there was no relationship between the two. On my FC drop, it is entirely possible my 80% SWG produced 3.3 of FC and this was not enough to keep it level.

On another note, I made my overfill pipe cap. Photos are below. I bought a 1-1/2" PVC coupling and 3" PVC pipe cap. I drilled a bunch of holes in half of the coupling and glued that into the cap. I sanded the ID of the coupling so it has a really loose fit on the pipe - easy to take off and add bleach.
overflow pipe.jpgoverflow pipe 2.jpgoverflow pipe 3.jpgoverflow pipe 4.jpg
 
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Thegatorvault

Active member
Jun 10, 2018
41
Tampa FL
Ok....might have figured out what is going on. I realized while resetting my Jandy SWG % that I have the dreaded 'No Flow' error. I have plenty of flow and I know the sensor is clean since I got this error around the time I was trying to figure out what was going on; my builder told me to clean it, which I did and it seemed to work again afterward. I read the 'daughterboard' reset trick but mine is circa 2018. After reading through a thread, I did stop the system and start it manually. The error went away. I Am assuming this happened after I cleaned it. So I called Jandy but of course they had no idea about the 'daughterboard' fix. They had me reset the breaker, so I will keep an eye on this tomorrow to be sure it is working during automatic startup. At least I appear to be making chlorine again (so far).

I am thinking now that this must ultimately be the root cause of my issue. I was away for work and then vacation about a month ago.....I think the 'low flow' problem must have started then, FC dropped, and before I was back in my testing routine, I must have gotten some kind of FC consumer in the pool. Thing is, there is no error message in the Jandy app....the only way you know there is a problem is by going to status screen and check it there, or by going to the panel. Sucks.