Trouble with FC levels/SWG

BoilerSim

Gold Supporter
Apr 22, 2019
38
Winter Garden, FL
Over the past few weeks I’ve been dealing with an issue with keeping my FC levels consistent. During the summer, I had no issues keeping our FC ~7.5 with a setting that added ~2.0 per day. This was with > 90 degree temps, direct sun, and almost daily rainstorms here in Central FL. However, for the past several weeks I have had to keep turning the SWG up higher and higher to maintain levels, and have had to supplement with bleach occasionally. I’ve now got it at ~3.5 per day and am struggling to maintain FC of even ~4.5. Temps are cooling and the pool gets much more shade this time of year, so I’m struggling to understand why this might be happening. Water is clear and my CC readings have been 0.

I cleaned my cell this morning for the first time since the pool was completed in the spring. Other than a small piece of debris, it was pretty clean and stopped bubbling after just a couple minutes. Only change I noticed is that my salt reading from the cell, which had been ~250 low, is now in line with my Taylor test kit results.

Anything I’m missing???
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,859
Sebring, Florida
Anything I’m missing???
Sure. Organics (algae) in your pool. Only sunlight and organics consume chlorine.....nothing else.

Since the sunlight (UV) is lessening, the only thing left is organics. I would suggest you perform an OCLT and confirm that but, unless your SWG has malfunctioned it really can't be anything else.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,647
Bedford, TX
BS,

The most logical cause is that you have algae, even if you can't see it.. This time of year your FC demand should be going down and not up..

That is why Allen asked you to run an Overnight Chlorine Loss Test or OCLT... I suspect that you are going to fail the test.

Thanks,

Jim R.
 

BoilerSim

Gold Supporter
Apr 22, 2019
38
Winter Garden, FL
Sure. Organics (algae) in your pool. Only sunlight and organics consume chlorine.....nothing else.

Since the sunlight (UV) is lessening, the only thing left is organics. I would suggest you perform an OCLT and confirm that but, unless your SWG has malfunctioned it really can't be anything else.
I will run an OCLT tonight. Wouldn't I see some evidence of organics in CC readings? They've consistently been at 0.
 

laprjns

LifeTime Supporter
Aug 14, 2012
364
Ellington, CT
Have you confirmed that the SWCG is running for the 10.5 hrs per day? Is the pump speed settings keeping the flow at a level that keeps the flow switch closed during those 10.5 hrs?
 

BoilerSim

Gold Supporter
Apr 22, 2019
38
Winter Garden, FL
So I ended up starting a SLAM Saturday evening as the pool lost 3.5 of FC in a few hours before I could even get to the OCLT. I saw what I needed to see at that point and went for it. Its been going pretty well so far. I initially started at an FC of 24 but stepped it up to 28 when I retested my CYA on Sunday. I'm a bit perplexed by how long it is taking, considering the water looked perfect all along. I know that doesn't mean it is clean, but five days feels like a long time. My OCLTs along the way have been as follows:
  • Saturday: - 5
  • Sunday:-3.5
  • Monday: -1 (decided to do one more day just to be sure)
  • Tuesday: -2.5
  • Wednesday:-2
It does seem like I'm making some progress (Monday could have been a testing error), but it feels like it is taking forever. This is my first time dealing with this, so I guess my question is, is this normal? Thanks!
 

mguzzy

Well-known member
Jul 8, 2015
794
OV, CA
Make sure you cleaning all the corners where algae can hide. I have a waterfall with its own intakes.. if I don't run it every now and then it will "hide" algae growth... And I recall a pool where He couldn't figure out where the algae was coming from after multiple slams.. they were in his roof mounted solar panels that he turned off whenever he slammed. Just sayin'

Around these parts a lot of organics have been getting dropped into pools from the smoke from the fires .. sometimes the source is external.
 

BoilerSim

Gold Supporter
Apr 22, 2019
38
Winter Garden, FL
Think I found the culprit. Was cleaning today and moved the river rocks in our water bowls around. Poof! Clouds of debris came out. I took them all out, cleaned them with a bleach solution, cleaned the bowls and will see what happens now. I also adjusted my program to run them four times per day vs the two I’ve been running them, as that clearly hasn’t been enough.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,809
Northern NJ
Depending how deep your bowls are it may be a chronic problem. If chlorinated water falls on the top of the bowl then it can roll off and stale water can stay at the bottom and algae can grow in it.

If there is nothing to mix the water in the bowl then running it more times a day may not be enough.
 

BoilerSim

Gold Supporter
Apr 22, 2019
38
Winter Garden, FL
Depending how deep your bowls are it may be a chronic problem. If chlorinated water falls on the top of the bowl then it can roll off and stale water can stay at the bottom and algae can grow in it.

If there is nothing to mix the water in the bowl then running it more times a day may not be enough.
They are pretty shallow. Maybe 9 inches of water. I would think having the river rock should disperse it a bit, but I could be wrong. Definitely something I need to keep a better eye on.