Pool hazy...always...bummer...

LouiseT

Member
Jul 7, 2020
7
Dayton OH
Hello! Seem to have difficulty with water clarity every year. A friend directed me to your site and I also finally bought a test kit. Here are the results from yesterday morning (July 12, 8:30am):

FC 12
CC 0.5
pH 7.8
TA 140
CH 170
CYA 60
Temp 82
Salt 3900
CSI (from pool math on this site) -0.01

I know the FC is too high. We have been having lots of 90 degree days and no rain. Pool is hazy and I have to work to see the bottom drain (only ~4.5 ft deep here). I would LOVE to have crystal clear water! Any suggestions would be much appreciated! Thanks!
 

Dtkokay

Well-known member
Dec 31, 2019
309
Houston, Texas
Hi there and welcome! Your numbers don’t look too bad, but the cloudy water is concerning. You probably have algae growing in the water. The best way to check for that is to perform an Overnight Chlorine Loss Test (OCLT). Check this web site for the exact procedure, but the short version is you are testing chlorine loss overnight to see whether you have algae. You would turn off your SWG as part of the test.

If you do have algae, then you should perform a SLAM, which is holding your chlorine at a very high level using liquid chlorine until the water clears up and you pass the OCLT. Again, check this web site for the exact procedures.

I’m very confident that you have algae but that it will go away and you’ll have clear water after a SLAM.

As for your other water parameters, your TA is a little high but I wouldn’t worry about it if your pH holds steady at 7.8. You CH is a little low for a plaster pool. I would increase that to at least 300.

Your salt reading of 3900 - is that from your SWG or the Taylor salt test? The Taylor test (as I recall) only provides results in increments of 200. SWG are not very accurate at reading salt levels. Mine read way high so I had to manually recalibrate according to what I tested using the Taylor test.
 
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LouiseT

Member
Jul 7, 2020
7
Dayton OH
Thanks for the reply! Wow that was fast! 😊 The salt number was from the test kit...and actually it seemed to be between 3800 and 4000...so I averaged for the 3900 (wasn't quite sure if I got the milky salmon color at 3800 so added another drop...but am guessing it was really 4000). I will try the OCLT test tonight. We have been having a few friends over fairly frequently for socially distanced pooI gatherings. If I have to SLAM how many days does that generally take and is it safe to swim during that period? Also should I go ahead and adjust the CH now or wait? Thank you so much!
 
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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,100
Laughlin, NV
Welcome to the forum!
Great job on getting a quality test kit!
Concentrate on getting the water clear and clean and then add the calcium needed to raise the CH.
Here is the procedure - Overnight Chlorine Loss Test. Read SLAM Process
A SLAM can take a few days to a couple weeks.
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
I suggest you read ABC's of Pool Water Chemistry.
 
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Dtkokay

Well-known member
Dec 31, 2019
309
Houston, Texas
I just noticed you have a sand filter. Those can take a little longer to clear up water. Just be patient and trust the process.

These days, biggest challenge is finding liquid chlorine. Walmart and your local hardware store are usually the best places.
 
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LouiseT

Member
Jul 7, 2020
7
Dayton OH
Sooo...I think I passed the OCLT. FC last night after sunset 7.0. SWG off overnight. FC this morning before sunrise holding at 7.0. Also...the pool is pretty clear today! Not perfect but much better. Pic attached-you can see the drain! (This is kinda like taking a car in that is making a noise and it stops when you take it in to the mechanic! 🙄) So few questions. Assuming I still need to bring the CH up to about 300—yes? Also thinking my sand filter may be why the water seems to be hazy so frequently? 🤔 Should I clean it or get new sand? (I backwash as needed. Gage typically at 12. I backwash at 15) Also seems that I am constantly vacuuming (2-3 times a week). I try to do it slowly so I don't muck it up. We have a gravel driveway and maybe the dust is adding to the issue. Grateful for your thoughts/recommendations! 😊 0A5FCA8A-8DA5-4F9A-BAB4-B53B492C600A.jpeg
 

LouiseT

Member
Jul 7, 2020
7
Dayton OH
Hello all—need your advice. Sorry in advance for a fairly long post. 🙄I began slamming my pool last Sunday Aug 9. Here are my readings at 1:40 pm before beginning slam:
FC 10
CC 0.5
pH 8.0 (subsequently dropped this to 7.6 before slam)
TA 140
CH 170
CYA 55
temp 82
salt 3800 (turned SWG off for slam)

Began SLAM that night. So I have been at this for a week. I have been vacuuming every morning and brushing the sides every morning and night. The water is clear. However every morning there is a layer of algae?dirt? on the bottom and sides. It is tan in color. I have read some of the info about yellow mustard algae and am wondering...I know it is fairly rare. However it occurred to me as I was vacuuming that we have frogs that frequent the pool most nights (we have a very small pond (12x5) about 30 feet from the pool). Anyway here are my FC readings:

8/10
7:15 am 27.5
1:30 pm 26
9:00 pm 22
8/11
9:00 am 21
3:00 pm 17
8:00 pm 24
8/12
9:00 am 20
3:00 pm 22
8:15 pm 22
8/13
8:30 am 15
6:30 pm 12.5
8/14
7:00am 25
7:30 pm 19
8/15
6:00 am 25
7:45 pm 15
8/16
10:00 am 28

We are heading out of town Friday for a week. As a side note—I believe the filter (5 years old) is functioning okay but have not had time to open it up to wash/change the sand. Water coming out of returns appears clear and the filter gage hasn't gone up.

So...My question(s):
1. Should I continue slamming until we go or change something?
2. I want to test to see where the other parameters stand soon and if necessary add chemicals to balance the pool before we go. I know pH will be off until FC drops below 10ppm. Would the other tests be accurate? Should I let FC drift down, test everything and adjust everything? Or worry about all of that when we get home?

So very much appreciate the help!