Cloudy water

[ultimateblazer]

Hi! this is my first post to this forum and am hopeful that an expert can help me out, as my local pool store has not been able to for several weeks.

I have a 18,000 gallon vinyl lined pool that has been cloudy for ~ 3 months. At the end of the last swimming season I replaced the sand in my Hayward S-200 sand filter, replaced a cracked Hayward Vari-flo valve that was leaking, replaced the polaris booster pump, replaced some pvc piping from the pumps to the filter, and installed a pool slide plumbed to the main pool pump with appropriate ball valves to bypass it when not in use. All of that took several weeks as I worked on it in my limited spare time, and the pool turned green from algae and filled up with leaves while the pumps were not running. When I got everything back together, I killed off the algae with some algaecide, and eventually got all of the leaves out with the Polaris. However, that was two months ago and the water is still cloudy. Visibility is such that i can barely make out the bottom step, and I can barely see the Polaris on the bottom of the shallow end. I tried running the pump 24/7 for several weeks with no improvement. I backed off to running it ~ 5 hours a day several weeks ago. Yesterday i took the Variflo valve apart and inspected the gasket to make sure that it was properly seated, and it was OK. Leslie's tells me the next step is Floccing it with some alum, but I am a little nervous about his as I am a relativity new pool owner and have never done this before. Thye also suggested running the pump 24/7 again.

I have had stable chemistry for at least 6 weeks as I have been testing every 2-3 days with my new digital Lamotte 2056 Color Q Pro 7 test kit.

Here's what I got yesterday:
FAC = 5.0
TAC = 5.0
PH = 7.6
Alkalinity = 101
calcium = 260
CYA = 73

any suggestions?

 

[Bama Rambler]

Welcome to TFP.

The first thing I'd suggest is running the OCLT (see my sig). That will tell us if it's something growing in the water keeping it cloudy of if it's a filtering issue.

How are you chlorinating the water?
What's the water temp?
What does the filter pressure run after a backwash?
How long are you going between backwashes?
What are you letting the filter pressure get to before you backwash?

If you're not using an swg, 5 ppm FC is at the very bottom of what's recommended or maybe even a little below.
I'd raise the FC up to shock level (30 ppm), run the OCLT and post the results.

We'll go from there.

 

[ultimateblazer]

I am running the test you suggested and will post those results in the morning.
As far as your other questions:

1. chlorinating with 3" chlorine tablets inline and Leslie's power powder shock broadcast. most recently i tried a gallon of chlorox as I have been reading about the BBB method and am interested in that, but have all 3 on hand.
2. 50 F
3. I just checked water pressure was 11.5 psi. backwashed thoroughly for 3 minutes until water ran clear in sight glass, and water pressure only dropped to 11 psi. it has been about 10 days since last backwash. I have been trying to avoid backwashing since pool store says dirty filters work better. don't really have a set schedule at this point.

It seems certain to me that it is a filtering problem. I have been tracking the chlorine closely for 6 weeks and have always had FAC almost equal to TAC with no major losses that would indicates something growing.

When I replaced the sand on my Hayward S-200 FILTER (200 LBS) I was careful to fill it half full of water before adding sand to keep the sand from snapping off the original plastic laterals. they all looked ok but they are 20 years old. what could I have accidentally damaged when I was changing the sand to cause this?

 

[y_not]

I would be willing to bet that you are experiencing some sort of algae or the growth of organics in your pool. A properly functioning and correctly sized sand filter will keep any pool crystal clear. Without the addition of any chemicals or filtration additives.

If your latterals were damaged, you would see sand in your pool. If they were clogged or collapsed, your pressure would be sky high.

Do you have a manial CYA test, the type where you pour a cloudy liquid into a sight tube until the black dot disappears at the bottom?

 

[Bama Rambler]

Since you're using trichlor and Cal-Hypo I suspect your CYA and CH numbers. Especially the CYA number.
Do you have any idea how much trichlor (3" tablets) you've used in total?
Do you know how much cal-hypo (power powder) you've used in total?

Your filter pressure looks good and since you're not getting sand back into the pool I'd say the laterals are ok.

Take a heavy sock and tie over a return and run the pump for several hours and see what's in the sock. That will tell us what's bypassing the filter and let us know if we need to look at the multiport valve as the culprit.

 

[ultimateblazer]

Bama Rambler - I have only been using Leslie's power powder and chlorox (once) since the trouble began. The inline tablet chlorinator is all eaten up so I have not been using it. I also added a bag of arm and hammer baking soda to raise the alkalinity from ~ 70 to 100 about 10 days ago. The replacement inline chlorinator just arrived yesterday and I'll replace it this week and start back using the 3" tablets. However, both my tester and Leslies agreed on the CYA levels of ~ 73. I have not been keeping records on amount of powder added but i will begin. as far as your sock suggestion, there are two returns and i doubt i could get a sock tie wrapped around one but I'll give it a shot.

 

[Bama Rambler]

The trouble with trichlor is that it constantly adds CYA and in most cases the CYA gets really high very quickly. The CYA test is one test where pool stores are notoriously wrong and the ColorQ can be wrong, thats the reason I questioned it.

Since you've been using cal-hypo since the trouble started it could be calcium clouding even at the level you have. Since you've been doing the things you have, it's a matter of ruling out things until we figure out what's causing it.

 

[dmanb2b]

Ultimateblazer, welcome to TFP

Algaecide - can not kill off an algae bloom, so you may still need to shock. While algaecide can in some cases prevent a bloom, once the water has gone green you need chlorine at shock FC level to eliminate the outbreak, followed by religiously maintaining adequate FC as it relates to your CYA level.

To answer your initial question on suggestions, I can offer the following:

- Perform the overnight chlorine loss test

- If you pass, it may in fact be a filtration problem and Bama has given you great advice thus far for checking the filtration system

- If you do not pass, it's time to confirm your CYA level and follow the shocking your pool process

Lastly, if the filter is working, make sure it runs 24/7 until the pool clears and if your CYA reading is accurate, you should be targeting a maintence FC of 6-8ppm, while shock FC level is somewhere around 28ppm.

Hope this helps some and feel free to read through our other articles in pool school (button on upper right of this page)