Help With Sand/Dirt Coming Back Into Pool

huskerfan

Well-known member
Jul 12, 2016
51
Lincoln, Nebraska
Pool Size
14000
Surface
Vinyl
Chlorine
Liquid Chlorine
Hey guys - wondering if you guys could help me figure out an issue I'm having with my pool regarding sand/dirt in the pool.

Right now, I have to vacuum it once a week, which I know doesn't sound terrible, but that week is me waiting until it gets bad enough to where I need to vacuum it. There will be bits of what I am thinking is sand spread throughout the pool the next day after vacuuming.

I vacuumed this past Saturday, then turned off the pump and closed the valves so I could take apart the sand filter as I figured I had a cracked lateral or a tear in the spider gasket on the multiport valve which was allowing sand to get back into the pool. By the time I got the sand filter torn apart, which took about a half hour, you could already see bits of sand had settled out over the bottom of the pool.

Upon closer inspection, it doesn't appear that there are any nicks/tears in the spider gasket, and the laterals all looked fine. cleaned everything up and put it all back together, and sure enough, the next morning the small accumulation of sand on the bottom of the pool had gotten a bit worse.

Any thoughts? Or is there something that I am missing? Any help/advice is greatly appreciated!

Prior to vacuuming picture below. I have the discharge jet pointed sideways to the pool gets a natural swirl, that's the reason for the debris accumulating in the middle:
Prior To Vacuuming.jpg

This is a close up of the debris - it looks like a lot of dirt, but could just be the ripples in the water:
IMG_0630.jpg

Close up of what looks like sand from the filter:
IMG_0631.jpg

This is a half hour after vacuuming and I had taken the filter apart. You can already see how much sand/dirt has settled to the bottom since the pump wasn't running:
30 Mins After Vacuuming.jpg

This is what the spider gasket looked like - looked fine to me, but not sure how those little bites of debris got underneath the gasket?
IMG_0634.jpg

Inside of multiport valve:
IMG_0635.jpg
 

Texas Splash

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I would recommend first let's be sure it's sand and not algae. If it's sand, you should be able to pinch it and collect it. You'll know. If it's organic material is will disperse quickly. If you can touch it, it may feel mushy or slimy. Can you confirm?
 

Texas Splash

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Jun 22, 2014
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I did that a couple times at the beginning of the summer and the dirt/debris would still return
Curious to know what you learn by trying to touch or capture that stuff. In the meantime, you can always consider doing an Overnight Chlorine Loss Test. Algae happens even when we think our levels are, or always have been, great. It's a lot easier to do an OCLT than opening p the filter to inspect laterals. If you pass the OCLT, it's back into the belly of the filter.
 

huskerfan

Well-known member
Jul 12, 2016
51
Lincoln, Nebraska
Pool Size
14000
Surface
Vinyl
Chlorine
Liquid Chlorine
Well guys, I was unable to perform the OCLT as we had a big storm that rolled through last night, but i was able to get in the pool before it hit and stir up the debris, and it appears to be dead algae - it definitely "poofed" up into a cloud when I disturbed it with my foot as you can see in the attached pictures. What is the remedy then? Just vacuum the dead algae to waste?

IMG_0657 (2).PNG

IMG_0658 (2).PNG
 

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ferretbone

In The Industry
May 24, 2016
209
tx
1. Not enough filter media in your filter. Vac to waste, to get rid of that dust. Top off the filter with a little more sand, or back wash more often.
2. That's getting blown into your pool. It's not dead algae, it's to dark to be dead algae. Dead algae is grey, white, or even tan.

That's dust/dirt getting blown in from the construction down the road, the new landscaping next door etc...

 

huskerfan

Well-known member
Jul 12, 2016
51
Lincoln, Nebraska
Pool Size
14000
Surface
Vinyl
Chlorine
Liquid Chlorine
Ok guys, I have been just vacuuming to waste the dead algae. Done it twice now, and did an OCLT this past Friday night/Saturday morning, and I did not have any CL loss overnight. However, I am still seeing an accumulation of dead algae on the bottom of the pool. What would be the next course of action?
 

IceShadow

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Jun 8, 2019
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How does the pool look? Is it really clear? If so, it's time to start searching for hidden algae. Any ladders in the pool? Any lights? Check the skimmer throats and weir doors, scrub around return jet and suction ports / main drains.
 

IceShadow

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Also - that could just be dust. It's hard to differentiate dust from algae. But still, check the hidden areas in case anything is hiding on you. OCLT passing is a good indicator it may just be dust getting into the pool.
 

huskerfan

Well-known member
Jul 12, 2016
51
Lincoln, Nebraska
Pool Size
14000
Surface
Vinyl
Chlorine
Liquid Chlorine
Pool is very clear, yes, just the debris/dead algae on the bottom in the middle. No ladders or lights in the pool. I will scrub the whole pool and report back.

I am having to add about 1/2 gallon of 12.5% liquid bleach every other day currently - is this normal for the hot and sunny part of the year? Would it be plausible that i have some small amounts of hidden live algea somewhere in the pool that is eating up my chlorine and making me have to add 1/2 gallon every other day?

I have a hard time believing that the debris is dirt/dust only because of how much accumulates in just a week. But i have been wrong before. Just seems like I shouldn't have to be vacuuming the pool to waste once a week.
 

IceShadow

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You could repeat the OCLT to be sure but if that passes, that indicates that only sunlight is eating your FC. FC doesn't take a break overnight on the algae killing. :)

1/2 gallon of 12.5% chlorine is 4.5ppm in your pool. That's on the high side but we are now at the summer solstace. You could bump your CYA up a little, say 10ppm, and see if that reduces the FC usage. Your FC has to run a little higher but your loss should be less daily.

EDIT: Sorry, missed you said every other day - that's only about 2.25ppm per day. Most pools need 2-4ppm of FC daily.
 
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huskerfan

Well-known member
Jul 12, 2016
51
Lincoln, Nebraska
Pool Size
14000
Surface
Vinyl
Chlorine
Liquid Chlorine
You could repeat the OCLT to be sure but if that passes, that indicates that only sunlight is eating your FC. FC doesn't take a break overnight on the algae killing. :)

1/2 gallon of 12.5% chlorine is 4.5ppm in your pool. That's on the high side but we are now at the summer solstace. You could bump your CYA up a little, say 10ppm, and see if that reduces the FC usage. Your FC has to run a little higher but your loss should be less daily.
Yeah I was thinking about repeating the test Saturday morning to confirm. I tested my CYA back on 5/18 and it was at 55, but I will do it again to see where it is at since I have vacuumed to waste a few times since then, which would have lowered my CYA.

That is low for this time of year. Adding every other day in summer can lead to FC falling below minimum. Be sure that is not happening.
Understandable. I have been steadily keeping it between 3 and 5 ppm on FC adding a half gallon every other day, only because adding everyday is a more difficult to do with my schedule since I am not home everyday. That being said - what are the cost savings from going the TFP route? I am not knocking it by any means, just curious as it saved me last summer when i had no idea why i kept having algae blooms, but what it wound up being was my CYA was wayyyyy too high. TFP saved me there.

But if you figure roughly 3.5 months of pool time in the summer (we'll go with 110 days for math's sake) and you add 1/2 gallon of 12.5% liquid chlorine every other day, that's about 28 gallons of liquid bleach each summer. 28 gallons of liquid chlorine @ $4 each, that's $112 in chlorine/summer, which is not terrible at all. But prior to my issue last summer, I had a 50 lb bucket of 3" tablets for $250 that lasted me 4 summers (About $60-70/summer). Again, not discounting the TFP method or anything! Just curious and asking questions :)
 

duraleigh

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We hope TFP saves you money by preventing the expense of algae blooms and bad pool store advice and mismanagement of your pool water.

Equally important, we hope it gives you the satisfaction of having a sparkling pool that you are proud of and don't fight with half of the summer.
 
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IceShadow

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Yeah I was thinking about repeating the test Saturday morning to confirm. I tested my CYA back on 5/18 and it was at 55, but I will do it again to see where it is at since I have vacuumed to waste a few times since then, which would have lowered my CYA.


Understandable. I have been steadily keeping it between 3 and 5 ppm on FC adding a half gallon every other day, only because adding everyday is a more difficult to do with my schedule since I am not home everyday. That being said - what are the cost savings from going the TFP route? I am not knocking it by any means, just curious as it saved me last summer when i had no idea why i kept having algae blooms, but what it wound up being was my CYA was wayyyyy too high. TFP saved me there.

But if you figure roughly 3.5 months of pool time in the summer (we'll go with 110 days for math's sake) and you add 1/2 gallon of 12.5% liquid chlorine every other day, that's about 28 gallons of liquid bleach each summer. 28 gallons of liquid chlorine @ $4 each, that's $112 in chlorine/summer, which is not terrible at all. But prior to my issue last summer, I had a 50 lb bucket of 3" tablets for $250 that lasted me 4 summers (About $60-70/summer). Again, not discounting the TFP method or anything! Just curious and asking questions :)
Every method has its ups and downs. Standard maintenance costs for the tablet method may be lower, but you'll be spending more to fix the issues that come up. It's all a trade-off, and personally the peace of mind and constant availability of an algae-free pool is worth it for me. :)
 

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