Murky / Opaque Water after 8 days of SLAM

[Ernak]

Hey TFP!
As a little background, I bought a house (my first) mid summer last year with a 18x36 IG (23,000?) gal vinyl pool (also my first).
After a few trips to the p∅∅l $tore, and a few shades of green later, I realized something they were t(s)elling me wasn't right. After discovering TFP I binge read every topic under the sun for a week or two, then 2-3 days of SLAM later I was crystal clear and enjoying my investment. - so thank you!!
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Sorry for what will inevitably be a very long post, but the TL;DR is:
After opening my pool(swamp) for the season using strict adherence to TFP methods, everything turned blue nicely, but it's been over a week and the water is still too murky to see the bottom of the shallow end. (the same murkiness level of 24 hrs after opening)
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Details:
Rewind to last Friday - I opened the pool (swamp), albeit a little late in the season from what I gathered (For Chattanooga) - All equipment back up and functioning normally - after a quick dose of MA, tests (Taylor K-2006C) showed
FC/CC - 0
PH - 7.2
TA - 50
CYA - ~10
CH - 20
(FYI Temp ~65F)

Threw ~2 lbs of CYA in a sock, and everything else looked ready to SLAM. Bought WallyWorld's stock of chlorinating liquid and got my FC up to 10-15 and maintained it. Swamp turned blue almost immediately, but still had the grayish hue of dead algae, and very murky. I had experienced this before, and expected it to clear up in AT MOST a week, but more likely ~48 hours based on past (sand)filter performance.

Checked CYA 48 hours in, shows 25ppm, added another 3lbs of CYA for good measure.
Performed two OCLT's Tuesday & Wednesday, both passed. Still murky, but more of a white hue, not so much gray. (Seemed indicative of high CH, maybe? But not according to the test...)
So yesterday I decided to turn my filter 'up to 11' by throwing in some DE (never had to try it before) . Carefully measured my 1/4 cup at a time, waiting 5 minutes between just in case. got to 3/4 cup and saw a 1psi increase, waited by the pump for 15-20 minutes or so, psi held. Went inside for 10 minutes, came back out and my psi had increased 50%. I did a very brief backwash, threw in just a pinch (1/4 cup) DE, started again. 1 hour later, no pressure increase (not even 1psi).
I get up this morning, only about .5 PSI increase, no change in water. (FC 14, CC .5)

So that's where I'm at now, spent almost my whole month's utility budget on electricity already, and am almost out of my 25 bottles of the elusive (in my area anyway) 10% LC, from maintaining SLAM for so long.
I'm going to try vacuuming again now, just in case there's something lurking down there that I missed, that could be causing this? That's my only remaining idea.
Feeling a little despondent... Any suggestions would be greatly appreciated. : )

 

[mknauss]

Welcome to the forum!
Sand filters take the longest to clear. You can keep doing the DE treatment. You can also try leaving the pump off over night and see if you get some settling that you can vacuum. But really, it just takes patience.
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[BuckeyeMac]

I’m right there with you...it’s been almost 2 weeks for me and I’m still cloudy. It’s getting better everyday, just very slooooooooooow. Almost to the point where you think something is wrong/or you didn’t do something correct ?

Trust what everyone says....patience. It’s just no fun waiting ?

 

[ajw22]

Have you opened up your sand filter to see what condition the sand is that you inherited with the house?

From Pool Filter Comparison - Trouble Free Pool

First we’ll look at Sand Filters. Some say sand is the easiest to maintain but its filtering ability is the lowest – down to about 30 microns. This can be particularly evident if your pool is lighted at night. Filter aids such as DE powder or cellulose fiber, however, can help improve sand’s filtering ability. Cleaning a sand filter is easy, when the pressure reaches 25% above the clean pressure, backwash the filter to remove the trapped dirt and debris. Backwashing is about a 10 minute process. The constant backwashing will tend to throw your water balance off but this can be useful if you use trichlor or cal hypo. Sand does occasionally need a more thorough cleaning than backwashing alone can do. Once a year open up the filter and insert a garden hose in the sand to let the water flush out all the crud that has collected in the sand until the overflow is clean. You might have to CAREFULLY break up the sand with something like a broom handle if it is clumped together, CAREFULLY so you don’t damage the laterals. If there is evidence of scale buildup on the sand, then an acidic sand cleaner might be needed to clean the sand of the scale.

And Deep Cleaning a Sand Filter

 

[Ernak]

Thanks for the encouragement guys - I took your advice and just toughed it out running the pump 24/7 and holding SLAM levels. I also routinely added DE (about once per day) and PSI slowly rose as expected, (which makes me tempted to rule out sand channeling as the culprit?) although now it's been another full week (2 weeks since opening) and I still can't see the bottom in the shallow end (see image), i'd say the water is marginally clearer, but not more than 20% or so. I'm thinking about trying to deep clean my filter tomorrow, despite the filter pressure having a healthy increase from the DE. My issue with that is I have a side-mount filter, and I've not seen any specific documentation on deep cleaning anything other than a top-mount... is the procedure different in some way?

 

[RNeumann]

Thanks for the encouragement guys - I took your advice and just toughed it out running the pump 24/7 and holding SLAM levels. I also routinely added DE (about once per day) and PSI slowly rose as expected, (which makes me tempted to rule out sand channeling as the culprit?) although now it's been another full week (2 weeks since opening) and I still can't see the bottom in the shallow end (see image), i'd say the water is marginally clearer, but not more than 20% or so. I'm thinking about trying to deep clean my filter tomorrow, despite the filter pressure having a healthy increase from the DE. My issue with that is I have a side-mount filter, and I've not seen any specific documentation on deep cleaning anything other than a top-mount... is the procedure different in some way?
View attachment 99570

I recently was having the same issue as you are now during my SLAM, except it went on for about 30 days. We finally opened up the filter and found the sand in terrible condition and almost all of the laterals broken. After we got the lateral assembly replaced and put new sand in the pool cleared up in a few days. Not sure if that is your problem but would definitely be worth it to check it out.

 

[borjis]

I recently was having the same issue as you are now during my SLAM, except it went on for about 30 days. We finally opened up the filter and found the sand in terrible condition and almost all of the laterals broken.

Thanks for posting that. I believe that has more to do with a pool not clearing up in a reasonable time than anything else.
And I remember some time ago a tfp user named Bruce was helping someone with a pool that wouldn't clear up...turned out
it had playground sand in the filter instead of the proper filter sand so it did nothing.

I often see some quick to jump on sand filters being so much slower. Well, in my experience they are not terribly slow at clearing water.
When I had to do a mustard slam, it took 2 full weeks, start to finish. The last time I brushed where dead algae came off the walls and
clouded the pool, my sand filter was able to get the water to crystal clear tfp sparkle within 72 hours. (pump running the entire time).

 

[Ernak]

Yes thanks for sharing that info. I will definitely open up my filter this afternoon and try to deep clean. Still not sure what the best method is, since it’s a side mount filter, but I’ll just wing it. Is removing the sand the only way to inspect the laterals? I don’t typically have any sand in the pool, so I’ve not worried about them in the past, but now that I think about it I noticed a line of ants making their way in and out of the filter when I first opened the pool, so I wonder if they damaged the sand or laterals in some way over winter.

 

[borjis]

Yes, unfortunately all the sand has to come out if you want to inspect the laterals.

 

[Ernak]

As a follow up - after deep cleaning the filter twice, adding more sand, adding DE twice a day for 1.5 weeks, I only saw a marginal improvement, and could still not make out the shape of leaves in the shallow end (~28 inches). This was a full 3 weeks into SLAM, with pump still running 24/7. After reading every thread I could find on clarifier, I decided it was an acceptable last resort for my situation. 4oz of hth clarifier and 8 hours later I could see leaves in the deep end (9ft), and now 48 hours later it’s crystal clear. Despite it being a bit of a risk (and arguably unnecessary), I wish I’d done it 3 weeks ago, would have saved me $200 on bleach and electricity lol