Water Will Not Clear, FC slowly dropping

[cdchris1]

We have had our pool for several weeks now, and I just cannot seem to get my water to be the crystal clear I know it can/should be. I can see the bottom without any problem, but there just seems to be a haze in it. I did a SLAM about a month ago due to a total loss of cholrine (no CYA) and a film starting to form on the water surface (first pool and new owner mistake). The water got pretty clear after, since then, my FC has been dropping slowly. I did an overnight chlorine test a couple of times and it is always less than 1ppm. However, I have had to crank my SWG way up (85%) to keep up (PB said I should be somewhere around 35-50%). I have not let the FC drop below 3 since the SLAM (I have had to add a small amount of bleach to keep up though). My PB was out yesterday and took a look. He tested for phosphates and said they were through the roof (+5000ppb), so he added some phosphate remover and gave me instructions to get some test strips and keep cycling the remover until they are below 1000ppb. He said that they could be coating the SWG plates and causing it not to work as efficiently as they should. He also threw in a bag of shock to get my chlorine up. He said that that should help clear things up. The rest of my last round of test results are below. I know my TA is high and I am working on that slowly. The CH is high as well, but not much I can do due to my fill water also being high. I am just wondering if I am still on the right track, or if there is something else I should be doing. Thanks for all of the help here.

FC= 3.5
CC= 0.5
PH=7.5
TA=230
CH=550
CYA=60-70

 

[JVTrain]

When you run the OCLT, have you tried elevating the FC to about 10 ppm to start the test? The OCLT is more definitive at elevated FC levels, such as when completing a SLAM procedure. Use bleach to elevate to 10 ppm, measure the FC and be sure to turn off the SWG to begin the test.

If you pass the OCLT at the elevated FC, maintain 5-6 ppm for a while after that to see if that helps.

 

[cdchris1]

I tried the OCLT at 9ppm (my first one was at 7), and it is still less than 1ppm. It has cleared up a lot since Friday though. Still not where I think it should be but definitely better than before. Despite what I have read, I am beginning to wonder if the phosphates might have something to do with it. I just hope it continues to clear up after a couple more treatments.

 

[UN1017]

Don't stress over the phosphates. How long are you running your pump?

 

[cdchris1]

We have been running it for 13 hours a day. I am hoping to reduce that somewhat, but I want to get everything cleared up before I play with the pump.

 

[MarianParoo]

I am also wondering: Was the SWG off for the OCLT?

 

[cdchris1]

I did not turn it off, but I did test after 10pm which is when my pump turns off, and the again before it turned on in the morning.

I do have another theory and am wondering how sound it might be. Our spa always seemed a little hazier in the morning than the pool. One the spillovers ran in the morning, everything would equal out. I never thought to test the spa water independently from the pool as the same water cycles through. I'm thinking I may have had an issue with the spa water and once the water ran into the pool, my chlorine would kill it. This could explain the loss through the day and the high SWG setting as well as why I always passed the OCLT. Between the shock my PB added and additional spillover cycles, the pool and spa look the same now. My daily chlorine loss has been down and I have backed off on the SWG setting to get it back down to around 5.

The phosphate remover also clouded everything up, and my PB added a lot. Maybe there is residual in the filter and he told me not to clean it for a week. Once I clean the filter, hopefully everything will clear up? I will do an OCLT on both the spa and pool as well if it does not.

 

[Swampwoman]

He said that they could be coating the SWG plates and causing it not to work as efficiently as they should.

Just so you know, I've experimented pretty extensively, talked to several mfgs, and even pool industry pro magazine columnists about this. Pentair goes on record saying It recommends phosphates below 500 ppb, which many feel is not a real world number.

Without bogging you down in all the nonsense in my experiments, I will tell you that my Aquarite t15 has steadily produced an accurate amount of FC per run time and rated output since April without ANY problem and with literally TEN TIMES your phosphate reading (due to heavy sequestrant use for years.) But tat particular unit does reverse its polarity which is supposed to help keep the cell clean.

With that said, I also have very low calcium (vinyl pool). It is possible that your high calcium is contributing to scaling on the cell -- both calcium and also calcium as it contributes to phosphate scale, so check your cell for visible scaling (though phosphate scale is not necessarily visible.) You could clean your cell in a mx of MA and water -- refer to your manual for the how to for your model.

Then, if you want to, check your pentair manual for cl gas output per 100% in 24 hours. Use Pool Math and enter the pounds of chlorine gas produced per day in your size of pool at 100/24...then calculate how many ppms of chlorine are supposed to be added each day at your current run rate and run time, and then calculate the amount you'd need to run it at 5 or 6 fr a spell.

See if by using that setting you can tell whether the cell produces as it should, assuming a consumption rate (just a guess) of about 2 ppm per day. That will help give you an idea if there's an issue with the plate or not. Most often, the answer is not...but you could be the exception.

Those steps would give you a more concrete sense of your cell condition. PB guessing at phosphates is quite possibly erroneous. You're better off to first rule out production/run time issues or test not guess