Slamming, CYA not increasing, still cloudy

TwinsPool

Gold Supporter
Silver Supporter
Oct 3, 2021
76
Los Angeles
Basically a newbie with SLAM/CYA/Cloudiness problems.
Brief history: Started with an many-months-old (ok, then, 2 years) swamp due to filter failure and slow repair of it. Layer of leaves and algae on bottom for a long time. I repaired the filter and installed a vacuum to waste valve between the pump and filter and have used that to clear the bottom. Now am trying to be serious (as my job allows) about SLAMMING but am having some problems with CYA and cloudiness.

July 18-20 (prior to vacuuming bottom): Added 5 lb of CYA (squeezing it out of a pillowcase) over 3 days, and added 3 gallons 12.5% chlorine with daily additions of 1 gallon a day (pouring while walking perimeter of pool) afterward to keep algae at least in check until I could really spend more time on a SLAM.
CYA test only went up from clear to cloudy but still <20ppm (readings over >7days were stable). However, since pump & filter have not been running (no disturbance of water), the water cleared rather nicely (almost crystal clear) due to the constant supply of chlorine and I could see easily details on main drain cover. But bottom very green with leaves and algae. Clearness disappeared for good after vacuuming bottom to waste and running pump/filter.

Aug 5-6: Added 2 lb of powderized CYA, but still <20ppm today (Aug 8).
Finished vacuum to waste during this time, and added the required 4.8 lbs of DE (poured ~5 gallons of DE slurry into skimmer) to my newly cleaned filter panels. However, the PSI on the filter did not seem to increase at all after adding DE. That seemed odd and PSI is not increasing while filtering, so yesterday (Aug 7) I took pictures of the DE-coated panels, etc, and will attach them below. Are my DE filter panels properly coated?

Here are my recent test results
Aug 5: FC 9.5, CC 0.5, CYA <20 Added 1 gal chlorine
Aug 7 (noon): FC 9.0, CC 0.5, CYA <20 Added 1 gal chlorine
Aug 7 (night, 1.5 hr after 1 gal chlorine added): FC 12.5, CC 0.5, CYA <20
Aug 8 (noon, sun on pool): FC 9.5, CC 0.5, CYA <20

Here is a picture of the pool today around noon (can barely see black&white striped vacuum head on bottom of deep end). Cloudiness is very slightly better than yesterday, but any clearing seems very slow:
IMG_5791.jpg

And here are pictures of the DE-coated filter panels and one where I spread some DE with a screwdriver to show clean DE under the dirty (are they coated correctly with enough DE??):
IMG_5788.jpgIMG_5789.jpgIMG_5790.jpg

I am running the pump at it's top speed 3250 RPM for filtering, which is probably stressful for it, since it is a 1.5 HP variable speed pump and the plumbing is 95% 1.5-inch stuff. Should I slow it down?

Also, I decided to draw water from the main drain and not the skimmer, thinking that most of the cloudiness is down low. Ok to do that?

Sorry for the long email, but just hoping to answer the most common questions right off the bat.

Will be so very grateful to get input on 1) my low CYA problem, 2) my persistant cloudiness, and 3) whether my DE filter panels are properly coated (oh, and should I slow down my pump?).

Many thanks!!
 
Will be so very grateful to get input on 1) my low CYA problem,
What is the temperature of your pool water?
Let's talk CYA testing...try this: Outdoors, sun to your back. Pour to the first line. Hold at your waist in the shadow of your body, GLANCE. If the dot is obscured, you are done. Take the number on the line and add 10. If not obscured, fill to the next line, hold at your waist, GLANCE. When the dot is obscured, you are done. Take that number and add 10. Continue with each "next line," until obscured, add 10, you are done.
2) my persistant cloudiness,
To clear the cloudy, particularly in the summer, you need to test and replace FC more often, up to every 2 hours, will really help. If you have to work, then do every two hours when you are home, until you go to bed.
and 3) whether my DE filter panels are properly coated (oh, and should I slow down my pump?).
They look fine. 4.8lb is correct for a clean filter.

Slow down the pump, 1500-2000 would be better, and you will get better filtration.

Clean the filter, reload DE. Note clean filter pressure. When pressure rises 25%, clean them again. You may have to clean often. You should note pressures when pump is on high speed, pick a number 2500-3000.
Do you have the ability to backwash or only clean?
Does your pressure gauge go to 0 when you turn the pump off? If not, replace the gauge.
 
Thanks, PoolStored!

CYA: At 9pm here (dark), 1 ft beneath surface, the water temp was 81F.
Thanks for the details on the CYA method. I have been examining the dot outdoors at waist height and in a shadow but probably not always with me standing in the sun and the tube in my shadow. I have been slowly filling the tube while looking at the dot but the dot never disappears (although gets mostly obscured when filled over the 20 line). Will use your method, including filling to lines and glancing, for better reproducibility. I'm kind of doubtful that my method of reading will give a different number, however.

• When you glance, do you make somewhat of an effort to find the dot, or do you only give youself only a second or so to find it readily? I found that if I slightly wiggle the tube bottom back and forth the dot is easier to see.
• Do you think I should I add more CYA? If so, how much? I should be way over 30 by now, but even 7 lbs so far doesn't seem to have produced expected results. Or maybe you're thinking I am being a bit too obsessive about finding the dot? ...I admit, that's possible, but I am able to faintly see the dot.

Cloudiness: I will try to test more often. I work from home (although it's been crazy hectic lately). I will test every 2-3 hours, starting tomorrow, since that seems important.
By the way, I just tested chlorine at 9pm and FC was 6.6 and CC was 0.5. (Recall it was 9.5 and 0.5, respectively, at noon today, so yes, I should test more often.) I will add two gallons after I send this, which could bring the FC up to about 13 or 14, at least temporarily, and I'll test in the morning.
• So, basically just keep on filtering while keeping the FC high is the key?
• I'll also try to brush all the surfaces as much as I can. That, and vacuuming, takes quite a bit of time for me it seems.

DE filter: I have been checking the filter pressure. It is only very slightly higher than just after fresh DE, definitely not 25% higher than when fresh (I tested it then at the 5 preset RPMs), so I guess I can leave it a little while longer? I will keep a close eye one it though at a higher speed as you suggest.
• By the way, do you know the best pump speed when adding fresh DE for good coverage of the panels (is slower or faster better)?

Pump speed: It has a preset pump speed at 1750 (the #2 of 4 speeds), so I'll go with that for filtering as you suggest.
Backwash... When we bought the house 3 yrs ago (only moved into it last summer), the backwash valve was frozen in the filter position. I rebuilt the entire filter it seems, so it functions now, but I have no place to put the DE backwash. So I have the ability to backwash, but I will only be doing full cleanings. Local Dept Water & Power suggests to put DE into the sewer, so I have a way to do that without too much trouble (basically spray them with a hose inside a mid-sized plastic trash can with funnel in bottom into a sewer cleanout in front yard). My vacuum-to-waste had to go through a 75-ft collapsible 1.5" dia hose out to the street.
Pressure gauge... Yes, it goes to zero when the pump is off. Thanks for thinking of that possible problem.

I appreciate your helpful comments very much and your patience with my wordy posts!
 
When you glance, do you make somewhat of an effort to find the dot, or do you only give youself only a second or so to find it readily? I found that if I slightly wiggle the tube bottom back and forth the dot is easier to see.
• Do you think I should I add more CYA? If so, how much? I should be way over 30 by now, but even 7 lbs so far doesn't seem to have produced expected results. Or maybe you're thinking I am being a bit too obsessive about finding the dot? ...I admit, that's possible, but I am able to faintly see the dot.
Glance. Don't wiggle. Should look like last pic.
1723206136365.png
I just tested chlorine at 9pm and FC was 6.6 and CC was 0.5.
Something is off. Use 10mL sample size. Each drop is .5FC and for reagent #3 (CC test), each drop is .5CC.
So, basically just keep on filtering while keeping the FC high is the key?
^^^THIS.
• By the way, do you know the best pump speed when adding fresh DE for good coverage of the panels (is slower or faster better)?
You probably don't need to do it at fully speed but I would at least have about 15 PSI of filter pressure when you do coat the grids. The most important thing when adding de is to have all the air bled out of the tank (de can't jump out of the water and pre coat dry grids).
 
This morning the FC was 15.5 (I added 2 gals of 12.5% last night), and the CYA dot was not obscured at the 40 line but was obscured at 30, so that means I should round up to 40 apparently. And that requires FC-16 for the SLAM. I ran out of chlorine last night and was too busy with work today to get to the pool store before they closed, but I went to Home Depot tonight for 2 gals of 10% and added that. FC was at 8.5 just before adding the chlorine. I should be more attentive this weekend.

I was happy to see that the CYA was stronger today for the first time since adding the initial 5 lbs 2-1/2 weeks ago (!) (and an extra 2 lbs 3 days ago). Will check again tomorrow.

Cloudiness seemed a tad bit better today, so I'm getting some optimism back.

DE filter psi is not rising, however, which is a bit unexpected to this non-expert. I think I better not replace it yet, since it may be harboring fine particles of CYA that I think I need (CYA dot was just barely opaque at 30 today--I'd feel better with a stronger call at the 30 line to possibly help protect all this chlorine I'm putting in there).
 
Great job on the CYA! Yes, 40!

I doubt there is any cya hanging out in the filter. Better to clean the filter than not.
How did you add the CYA to the pool?
What speed are you running the pump?
What speed are you checking the filter pressure?
 
Thanks for getting back to me, and sorry for my delay -- I was concentrating on another post where I asked about the staining in my pool, ie, whether it was black algae or metal stains (looks like the bottom has the measles). I'm thinking it must be stains from all the leaves & algae that were there for so long (maybe). I worry about it, because I don't know what it is, and don't want to swim if it is unhealthy. Maybe if you have ideas about that, I am all ears. The family is giving me a lot of heat for not fixing the pool in a reasonable time.

To answer your questions:
•I added the initial 5 lbs of CYA granules from the pool store by putting it in a pillowcase. That took 3 days of squeezing to get 95% of it out (thread count too high and granules too big). I ground up the 2 lb of granules into powder and put it into newish athletic socks. That worked much better. All out reasonably quickly (maybe an hour of squeezing all combined). That was about 10 days ago.
Unfortunately, the CYA is now back to 20. so I will be adding more CYA again.
•I've been running pump at 1750 rpm 24/7.
•I just checked the filter pressure a few minutes ago and it is only 17psi at 2500 rpm (haven't changed it yet during whole SLAM.) With new DE, it was 16psi. Maybe I need to add a little more DE next time?

I haven't been that good at brushing and vacuuming, but I did do a comprehensive vacuuming yesterday (slowly, at 1750 rpm). I don't see green on the bottom, but there are dark stains.

Some of my OCLTs are 1.5 recently, but today it was 3 (maybe I check too late in the morning?).

The pool looking much clearer (easily see drain and details on bottom), but still has some cloudiness. Cloudiness continues to improve ever so slowly. I agree the DE should be changed (completely), so I will do that after I send this.
 
Brushing twice daily is more important then you think because it won't let the algae stick and once it's in the water it gets killed off. If you don't follow the OCLT by the guidelines you won't really know what it's telling you
 

Enjoying this content?

Support TFP with a donation.

Give Support
Two days ago I removed my DE grid panels from the filter and found 3 of 8 had significant holes in them. I replaced them (with new DE of course) and today the water is crystal clear (was also very clear yesterday). Two days ago I also added 2 lbs of powdered CYA (powdered from granules), but it barely moved from 20 to 30 (read it today). OCLT test was passed after this also. No visible algae (although I will try to regularly brush from now on). CC was 0-0.5 (hard to tell which). So now I am moving on to balancing the chemicals. Pool Math says my TA is too high, CH is too low, and CYA is not is not ideal (a bit low, in other words). Here are the numbers today:
FC 8.5 (coming down from SLAM)
CC 0.5 (sometimes this is 0.0, but was never higher than 0.5 during long multi-week SLAM)
pH 7.8
TA 160
CYA 30
CH 200
CSI 0.29
Temp 78F

I suppose I need to add some acid to bring down pH and increase TA. I was going to start with 16 oz of the highly conc'd (31%) muriatic acid. Any suggestions, advice?
 
You do not need to increase your TA. pH is good for now; if it goes over 8 reduce it to at least 7.8. As you lower pH with MA it will reduce the TA.
 
Leave your pH alone until it gets to 8.0. In general, a pH in the 7s is just fine.
I'd manage pH and ignore TA. When pH gets to 8.0, reduce it to 7.4, this will also lower TA. Over time, pH will rise on its own, without affecting TA. When your TA reaches 80, stop forcing pH down, it should be stable around 7.8-8.0 which is just fine.
Raise your CH to 250.
Test your fill water for TA and CH.
Use pool math to calculate all required additions. Link-->PoolMath
 
  • Like
Reactions: oledan
Oops, I saw where I mistakenly wrote that I need to *increase* TA (it's high already!). I need to proofread more carefully.
Good advice, both of you. Thanks.
In the mean time, I've also read other posts saying that TA will come down when keeping pH in the 7s, so I now understand that normal procedure.

Fill water: CH is 75-100 (hard to tell, maybe slightly more color change at 100), TA is 100

One reason that I would like to bring down TA concerns these terrible stains that are even more disturbing now that I have crystal clear water. Although I don't have proof yet, I think they may be copper stains due to color of the stains and the pool surface in general and the stain's complete resistance to brushing. I was advised to use Jack's Stain Identification Kit to determine if they are metal stains. However, the kit requires a well balanced pool water to start with, including TA of 80 or below, FC of 1-3 ppm, and pH or 7.0 to 7.4, none of which I have at the moment. And I'm not sure I should go to FC 1-3 with a CYA of 30. Ugh, I'm in a bind here.

If anyone has ideas about these stains and how to get remove them, please chime in. I have another thread with pictures, etc, where I am asking about the stains, but it's not getting much attention. Here it is: Help please -- black algae or stains of some sort?
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.