Crystal clear water secret?

PoolBrews

Well-known member
Oct 16, 2019
190
The Villages, Florida
Hello all!

I've been on TFP for a little over 4 months now. I have a new gunite pool (WetEdge finish).

I'm having an issue keeping my pool crystal clear. About 8 weeks ago, I did a SLAM because the water wasn't crystal clear. This took about a week, and all looked good for a couple of weeks. I test every couple of days, and my numbers look good.

About 2 weeks after, the slight haze came back. I reread the SLAM instructions again and thought maybe I didn't SLAM long enough. I SLAM'ed again - this time it took about 10 days, and I waited to pass the overnight test 3 days in a row before declaring success. Pool was pristine - crystal clean and looked great for another couple of weeks.

During this time, my numbers have been all in range, and my FC has slowly dropped to 8ppm. The lowest it has dropped was to 7ppm 2 days ago. We had an all day rain on Sunday, and this morning I noticed the haze returning - not quite crystal clear. I think it may have even started yesterday (Monday).

One other point worth mentioning - each time the haze shows up, I see some large white flakes in the water. If you touch them, they fall apart. Once the SLAM is done, they are gone.

Test Results yesterday:

FC: 7
pH: 7.4
TA: 110
CH: 489
CYA: 75
Salt: 3400

What am I missing? I thought if the SLAM was successful, and I kept my FC up above 6ppm, I would keep seeing crystal clear water.
 

PoolBrews

Well-known member
Oct 16, 2019
190
The Villages, Florida
I am using the TF-100 kit. Must have hit something wrong on the keyboard - CH is 475.

I was using 75 for CYA because I ran the test twice and got 70 the 1st time and 80 the 2nd... I know it's somewhere between them, so I entered 75. I know I'm supposed to round up... but the dot definitely disappears before I hit 80 on the cylinder.

Thanks kimkats! I can't believe I missed that - I looked at the chart for SLAM and somehow missed the range of 9-11!

I still don't understand why my water would lose clarity when I never dropped below minimum FC. Would an all day rain do that?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
17,116
Bedford, TX
pb,

If you never close your pool, you should only have to SLAM once in a life time..

Not sure what, but something is just not right here.

Are you running the Overnight Chlorine Loss test, before and after you SLAM?? Overnight Chlorine Loss Test

Thanks,

Jim R.
 

PoolBrews

Well-known member
Oct 16, 2019
190
The Villages, Florida
Never ran it before I SLAMed - only after. The first time I stopped the SLAM after I passed the OCLT the first night - or so I thought. The 2nd time, I made sure I passed on 3 straight days before stopping.

Why would I do it before I SLAM?

FYI - I have owned two previous vinyl liner pools - one 42K gallons chlorine for 15 years and the 2nd was an 18K gallon SWG for 10 years. Never had this issue with either of those. This is my first gunite pool.
 

PoolBrews

Well-known member
Oct 16, 2019
190
The Villages, Florida
I read the CYA/Chlorine chart wrong - 9-11 is for non-SWCG pools. I have a SWCG, so at 80, my FC should be 6... which means I have not been below my recommended FC since the SLAM. So - I'm at a loss as to why my pool starts getting cloudy.
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
985
Prosper, TX (DFW)
PoolBrews - Sorry you are going through this. I took a peek at your PoolMath logs and while you had a few times of elevated chlorine at 10-14, that is nowhere near your SLAM level. I also see a few times ~2 months ago where you had 3 or less FC and one time with 0.

Since its cloudy, you know something is brewing. I would get it up to the real SLAM level (31 for a CYA of 80) and keep it there until you pass the SLAM criteria. That way you can completely knock out whatever is going on in your pool, then start enjoying your crystal clear water.
 

PoolBrews

Well-known member
Oct 16, 2019
190
The Villages, Florida
I didn't enter numbers during either SLAM since that was the only thing I could monitor during a SLAM. My last SLAM started on March 15th and went until the 25th. You will only see the log postings on the 15th during that time, from before I started the SLAM.

I do have a record of my FC and OCLT numbers during that time, if that helps.

My CYA at that time was 60, and my FC was consistently between 24 and 28 from the 16th until the 25th. I had crystal clear water on the 17th, just didn't pass the OCLT until the 24th, 25th, and 26th. (Yes, I waited for 3 full OCLT passes before stopping this time.) I did have to add less chlorine each day, and my OCLT started showing less loss each night after the 17th.

I'm an electrical engineer and career long IT guy, so this process makes logical sense to me. My pool is in a screened birdcage and is half protected from the sun (I have a canvas top on 1/2 of the birdcage). I don't get dirt and leaves blowing in, and my pool sees less sunlight than others in Florida. The only thing that gets in my pool other than SWG chlorine and muriatic acid would be rain through the screen. I'm having a hard time figuring out what is causing the slight haze in the pool when all of the numbers look good.

You can look at my logs since the 28th - does anything standout to you? You can see where I'm coming off the SLAM on the 28th (that's where FC was low enough to start running all of the tests again), and you can see FC drop from 11.5 to 7.0 over a week or so... then I saw the haze yesterday, possibly starting on Monday - right after the all day rain on Sunday.

I can do the SLAM again, but that takes time and chemicals and lots of TF-100 drops, and at this point I'm not sure that I know the root cause and this will not return again.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
44,916
Tallahassee, FL
Have you pulled out the light? How about scrubbed around the returns and inside the skimmer (make sure to check the skimmer door) with a tooth brush?

I still say keep you FC on the higher side. 6 did not work before so go higher and keep it there and see what happens. To me that will be easier than having to keep doing SLAMs.
 

PoolBrews

Well-known member
Oct 16, 2019
190
The Villages, Florida
Pool is new - completed November last year, so no, I have not pulled out my light. I brush the walls regularly and then run my S200 to clean after brushing. My 3 returns look perfectly clean, but get brushed along with the walls.

I used to run my pump 8 hours a day - after the first SLAM and the return of the haze, I have been running it 24x7 at 40%. I thought that would help to stabilize my chlorine production and provide better filtration. When the heater kicks on (about 1 1/2 hours each morning right now), pump goes up to 85%.
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
985
Prosper, TX (DFW)
My pool was also finished in November as well, and I bet that is frustrating. I doubt it has anything to do with the filter since the haze goes away when you SLAM, but have you cleaned your filter at all?

I would be tempted to clean the filter, scrub everything Kim mentioned, do another SLAM + an extra few days for good measure, then make 8-9 FC be your new target.

Thats all I've got. Good luck.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
33,412
Sebring, Florida
If you have been keeping adequate chlorine, filtration is the issue. What is the clean psi on your cartridge filter. What is it now?
 

PoolBrews

Well-known member
Oct 16, 2019
190
The Villages, Florida
During both SLAM's I pulled the filter, and replaced with a cleaned filter following the SLAM. I have 2 filters. I swap them once a month regardless (I really wish they had put a bigger filter on this pool!). When I swap, the old filter gets hosed off, soaked overnight in a TSP bath, hosed off the next day with an Aqua Comb, then stored for the next swap.

I started a new SLAM this morning - should I put the clean filter in now? Pressure is fine on the filter - no change since I swapped several weeks ago. My thinking would be to wait and replace after the SLAM - that way if there is anything in the filter, the chlorine should kill it before I clean it again and then I'm starting with clean water and a fresh filter.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
33,412
Sebring, Florida
I think we posted at the same time. There is no "secret" to crystal clear water. It's all about killing organics (chlorine) and filtration.......it's that simple.

If you are using adequate FC and can't clear your pool, then filtration is likely inadequate.
 

Cavmedic

Gold Supporter
Jun 10, 2019
83
Seminole, Florida
I would consider pollen as well.
I am in Oviedo and the pollen is bad. I have had to partial slam 3 times now. Lat time it rained and dropped all the pollen off the screen enclosure into the pool. Everything gets hazy. Raise FC to about 20 and 12 hours later water is crystal clear.
 
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PoolBrews

Well-known member
Oct 16, 2019
190
The Villages, Florida
When I set my pump to 100%, the psi has gone up by 2 (from 14 to 16) since I finished the SLAM and put the clean filter in.

I never run my pump at 100% - it's either 40% or 85% when heating, but I set the starting psi using 100% when I swap filters.

My next filter swap is due in 10 days, so this filter has been in for 20 days.