Particles in the water seen only at night w pool lights on?

lka674

0
LifeTime Supporter
Jul 12, 2012
106
Williamson County, Texas
Hi there....

This was the first time since I've started the BBB method that we have left to go out of town for several days.

Prior to leaving, I prepared by adding enough liquid chlorine so that when we came home this morning my chlorine would hopefully be at target. I loose about 1ppm typically.

While we were gone (3 days) we had some pretty heavy thunderstorms that we knew had dumped a bunch of water into the pool, so I was expecting a bit of a mess, however I was pleasantly surprised...I THINK, but a little unsure of a couple of things.

A bit of history...we've always had a high CH and I've been managing it by keeping the CSI slightly negative to prevent scaling until we could do a partial drain/fill in the fall.

Friday morning before we left (and after I bumped up my chemicals) my test results were:

FC - 11 (intentionally raised it for our absence)
CC - 0.5
pH - 7.0 (intentionally dropped it down from 7.3 since we would be gone and we have a lot of aeration so it goes up .2 -.3 overnight)
TA - 70
CYA - 60
CH - 520ish (the norm for us)
Temp - 86 (we fluctuate between this and about 90 due to our very hot summers)

When we got home this morning at 1:00am(yep...2 1/2 hrs ago), the pool water appeared crystal clear, however there was quite a bit of tree debris and leaves, etc on the floor due to the storms. My cleaner cannot be left in the pool, so the floors were not being cleaned while we were gone.

I was elated over the crystal clear water, so I did a little bragging to the DH (who also commented on how great the water still looked) , went and grabbed my fancy little TF-100 and speedstir and got after it.

FC - 8 :party:
CC - 0.5
TC - 8.5
pH - 7.3ish :whoot:
TA - 40!!!!!! :shock:
CYA - 55 :-D
CH - 400!!!!!!! :shock:
Temp - 79....CRAZY low for us at this time of year, so things cooled down with those storms for sure.

I mean, I knew it had stormed pretty bad, but WOW....almost enough to "fix" my CH problem and totally jack with my TA level that much???

So....I backwashed, cleaned all the skimmers and filter baskets :blah: and threw the ole Dolphin into the pool to start cleaning up the floors and walls and went ahead and started the process of adding baking soda a bit at a time to bring the TA back up to my target.

Anyway, while the water "looked" very pretty and crystal to clear and no visible signs of any algae etc.....once flipper started doing her thing I started noticing tons of tiny little particles floating under the water only visible in front of the underwater lighting when the water was stirred up....but a LOT of little particles....enough to make you think to yourself, "no way in the world would I ever even think about getting into that water".

This all being said though.....should I BE in a shocking process because of those particles? I was completely happy with the test results other than the way low TA, so I didn't think I needed to...but if I don't, does that mean whatever these tiniest of little particles are, will not go away and WHAT are they exactly? I was thinking maybe some biological things brought in with the rain, but clearly not enough to do too much damage to my chlorine loss, CC's, or water clarity.

Also, now that my CH has dropped to 400, do I really need to keep maintaining a slight negative CSI to prevent scaling? I realize 350 is preferable, but I almost fell out of my chair seeing that it had dropped 120 ppm just from the rain....that's a lot of dilution considering the pool calculator was telling me I needed to drain 67% of my water volume to get it to 350 for the past 2 months. Can this be an error??

Many thanks for any replies or comments.

Laura
 
Re: Particles in the water seen only at night w pool lights

Don't run 24/7. The pH won't go up quite so much, the alk won't go so far down, and the chlorine demand will go down.

From your CH readings, you had a lot of rain. Expect your pH needing to be higher as a result of the lower CH level. Always keep the CSI slightly negative.

Cartridge and sand filters have particles seen only at night and when the lights are on, especially if they've been recently cleaned/backwashed.

Scott
 
Re: Particles in the water seen only at night w pool lights

lka674:

PoolGuyNJ brings up a great point about filter run time. Most people tend to run their filters more than they need to. With water features such as spill-over waterfalls and fountains, the aeration will cause pH to drift up. Also, the extra run time is usually unnecessary for a well-maintained pool (unless one is going through the shock process) and is a drain on your electric bill. A good rule of thumb is to aim for a daily water turnover of around 1. With a VS pump, you have several choices on how to achieve this, so it may take some experimentation.

One thing you can try to reduce the amount of particles in the water is to add either DE or cellulose fiber (e.g., Fiber Clear, ZeoFiber) to your sand filter. I use this method (using cellulose fiber) and it does make a difference in the appearance of the water under the lights. Just keep an eye on your filter pressure, especially when first using the product as it may filter out more particles that have been passing through the sand filter all season. Here's the process on how to add either product to your sand filter: http://www.troublefreepool.com/pool-school/add_de_to_a_sand_filter. This article focuses on adding DE. The process to add cellulose fiber is the same, just follow the dosing instructions on the product label.
 
Re: Particles in the water seen only at night w pool lights

Thank you both!

Currently, I'm running the pump 14 hrs/day....and it's STILL more than I think I would like as far as efficiency is concerned.

12 hrs on low speed at 1950 rpm's b/c this is the speed in which my skimmers still work
2 hrs on high speed at 2900 rpm's.

I realize this is turning over the pool more often than need be, but we have crate myrtles....and if you are familiar with those, they wreak havoc on pools....so we've ran it more often during summer so the skimmers can keep up a bit better, otherwise we are out there having to skim more than we want to and we even have a fabulous little solar breeze skimming bot that works wonders, but sometimes can't even keep up with the petal debris. We are pulling the main trouble maker out this winter and replanting with something less intrusive! ;-) If we didn't have that issue however, what would you suggest as an appropriate pump running schedule and/or speed setting? I've gone back and forth so much on it I've started confusing myself. LOL

I currently have it set to run on high speed from 8-9 am, then low speed from 9am - 9pm, and then high speed again from 9 - 10pm and then off till the next morning.

I like the adding DE to the sand filter idea....thanks for the instructions on that as well.
 
Re: Particles in the water seen only at night w pool lights

but I almost fell out of my chair seeing that it had dropped 120 ppm just from the rain.
It didn't. Assuming your pool depth averages 4' (48") and you got 4" of rain, that's an 8% dilution so your 520 CH optimistically would have gone to 480.

There is an error in there somewhere but if you started legitimately at 520, the math is pretty straightforward and will not result in 400 unless you got around 12+inches of rain.
 
Re: Particles in the water seen only at night w pool lights

It didn't. Assuming your pool depth averages 4' (48") and you got 4" of rain, that's an 8% dilution so your 520 CH optimistically would have gone to 480.

There is an error in there somewhere but if you started legitimately at 520, the math is pretty straightforward and will not result in 400 unless you got around 12+inches of rain.

That's what I sorta thought too....but I've tested the CH weekly since I started this b/c I've been trying to lower it via backwash etc over the last 2 months.....It WAS at one point 550 2 months ago. I did a few large backwashes and got it down to 520 about 5 weeks ago and it's been constant at 520 since then. Tested it at 1am this morning after we'd been gone and it was 400....tested it again just a minute ago and thought maybe my lighting was REALLY bad or I was just REALLY tired after driving home in the middle of the night for 8 hrs...and I got 410 (so my outside lighting at 1 am with the speedstir backlight did affect the test result slightly). Doing the test the same as I've always done it and with the TF-100! Checked the rain total for the 19th...the day of our bad storms..and we only received 3 inches...

REALLY confused! :?
 
Re: Particles in the water seen only at night w pool lights

If you tested soon after the rain and before the water was well circulated, then the water near the surface would have more rainwater compared to water at depths. You could try having your sample tube be upside down, then inverting it to capture water at a much lower depth to see if you measure a difference. Usually you want to measure about a foot below the surface, but for this test see if you can go lower than that. Do you have floor drains or pop-ups or anything that would give you good bottom circulation (including pointing the returns downwards)? I suspect that your returns are pointed slightly upwards to create good surface action to take surface debris to the skimmer.
 
Re: Particles in the water seen only at night w pool lights

chem geek said:
If you tested soon after the rain and before the water was well circulated, then the water near the surface would have more rainwater compared to water at depths. You could try having your sample tube be upside down, then inverting it to capture water at a much lower depth to see if you measure a difference. Usually you want to measure about a foot below the surface, but for this test see if you can go lower than that. Do you have floor drains or pop-ups or anything that would give you good bottom circulation (including pointing the returns downwards)? I suspect that your returns are pointed slightly upwards to create good surface action to take surface debris to the skimmer.

Thank you Chem Geek....the storms rolled in during the wee morning hours on Sunday and I did my testing around 1am this morning, so maybe 20+ hrs or so after. I did learn from this site during my initial schooling on how to test that I needed to have the tube upside down upon entry, go down at least to elbow depth and then to invert to sample from lower depths, and I did do that, however you may be correct that it isn't deep enough.....I'll try it again here shortly going deeper. We have floor drains, and the only visible debris I see is that which was too large to be sucked into the drain and therefore required the pool cleaner.

You are correct about the returns. We do have them all pointed up due to the large amount of white petals that are constantly falling onto the surface and if the wind blows...I swear it looks like it's snowing into the pool. Currently my skimmer bot (solar breeze) is getting a software/hardware update and so we needed some help shifting that mess to the pool skimmers. Should our goal really be to keep them pointed down?

*********************UPDATE*****************************
Just went and retested the CH and I took the tube down to arm pit depth before inverting to collect sample this time.

CH = 410

The sample began turning purple around 320 or so and was truly blue at 410....I'm completely stumped, because you would think that if it was from rain dilution alone then wouldn't my CYA also have dropped significantly? CYA moved from 60 to 55 (8.33% decrease)...I would have thought it would have been more considering the CH test decline of 21.15%!! Strangely enough, based upon previous member's calculations, my CH decline based on the rainfall should have only been about 8%ish too. Should the percentage loss for CYA and CH be about the same?

The only thing I do know here with certainty is that the testing was performed exactly as instructed with very precise tube measurements (I have the tftestkits.net's sample measurement tool and even still I always verify it visually on the tube) and it was taken from the same sample site and depth that I've been going to for the past 6-7 weeks and getting tests of 550 initially and then 520 after some small drain/fills via longer back washing times.

Can TA falling drastically as well, have any bearing on the CH test? I only ask because the TA was the ONLY other test that I did that had any significant change. From 70 Fri to 40 (42.86% drop)...but everything else was within range to reach my CSI target range...including pH, which I thought would have been all over the place between 1 am and now, but is unchanged. I did add about 64 oz of baking soda right after my testing at 1 am to up the ALK, but that is the only substance I've put in the pool since before we left on Friday.

Test results as of 2:00pm today:
FC - 8 (down from where I increased it to 11 on Friday, exactly 1ppm daily loss)
CC - 0.5
TC - 8.5
pH - 7.4 (aerating to reach 7.5 and then holding)
TA - 70 (due to adding 64 oz of baking soda to get it up from 40)
CYA - 55
CH - 410
Temp - 84
CSI -neg 0.13

Other than some debris on the floor that I had to clean up with the pool cleaner early this am, the pool water itself is gorgeous and crystal clear at the moment ....hard to complain! Just clueless as to all those particles I saw in the dark within the pool light's glow (unless it truly is the norm from a sand filter and I've just never noticed it before...will check again tonight and maybe consider adding DE if it's still there, but the CH.....:scratch:
 
Re: Particles in the water seen only at night w pool lights

One can get a CH and TA drop of equal ppm magnitude (absolute, not proportional) with calcium carbonate scaling or precipitation, but your CSI was quite negative and besides, while your TA dropped by 30 ppm your CH dropped by over 100 ppm. The magnitude of change you are seeing is truly exceptional. Rain dilution (with overflow rather than evaporation) would lower everything proportionately though TA wouldn't get lowered as much since rain water does have a little TA (from carbon dioxide getting into the water droplets). I don't have a good explanation for the 23% drop in CH, the 43% drop in TA, but only an 8% drop in CYA. According to historical weather reports you had 5.25" of rain on Saturday so with a 4.5' average depth pool that would be only a 9.7% dilution so that's more consistent with what you saw with CYA, but not with CH and especially not with TA.
 

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Re: Particles in the water seen only at night w pool lights

chem geek said:
One can get a CH and TA drop of equal ppm magnitude (absolute, not proportional) with calcium carbonate scaling or precipitation, but your CSI was quite negative and besides, while your TA dropped by 30 ppm your CH dropped by over 100 ppm. The magnitude of change you are seeing is truly exceptional. Rain dilution (with overflow rather than evaporation) would lower everything proportionately though TA wouldn't get lowered as much since rain water does have a little TA (from carbon dioxide getting into the water droplets). I don't have a good explanation for the 23% drop in CH, the 43% drop in TA, but only an 8% drop in CYA. According to historical weather reports you had 5.25" of rain on Saturday so with a 4.5' average depth pool that would be only a 9.7% dilution so that's more consistent with what you saw with CYA, but not with CH and especially not with TA.

I know...it's craziness I tell ya! Nothing makes sense to me......
 
Re: Particles in the water seen only at night w pool lights

Since you have recently been backwashing your filter multiple times, I believe your filter isn't as efficient as it once was when it was dirty and maybe it released some particles back into the water. Sand filters will filter finer when they are a little dirty. The DE should help clean up the water, but watch the pressure as it most likely will rise much quicker.

When testing CH I have found that my test results are far more accurate if I add R-0012 to the water first. My CH is about 260 and I add 20 drops of R-0012 first, then I add the R-0010 and R-0011L as directed. When I do this, the test does not turn a purple color and I go straight to blue when I reach my test end point. When I follow the directions and add R-0012 last, the test turns purple first and it is very difficult to determine when the test turns blue. This might account for some of the differnce you are seeing. For your test I recommend adding around 30-35 drops of R-0012 first then finish the test. You need to count the 30-35 drops of R-0012 in your final reading. The CH test is so much simpler for me since I found this suggestion here at TFP.
 
Re: Particles in the water seen only at night w pool lights

ping said:
Since you have recently been backwashing your filter multiple times, I believe your filter isn't as efficient as it once was when it was dirty and maybe it released some particles back into the water. Sand filters will filter finer when they are a little dirty. The DE should help clean up the water, but watch the pressure as it most likely will rise much quicker.

When testing CH I have found that my test results are far more accurate if I add R-0012 to the water first. My CH is about 260 and I add 20 drops of R-0012 first, then I add the R-0010 and R-0011L as directed. When I do this, the test does not turn a purple color and I go straight to blue when I reach my test end point. When I follow the directions and add R-0012 last, the test turns purple first and it is very difficult to determine when the test turns blue. This might account for some of the differnce you are seeing. For your test I recommend adding around 30-35 drops of R-0012 first then finish the test. You need to count the 30-35 drops of R-0012 in your final reading. The CH test is so much simpler for me since I found this suggestion here at TFP.

So, I just went and did this...added 30 drops of R-0012, 20 drops of R-0010 and 5 drops of R-0011...it still turned it pink. Started adding R-0012 to it and it continued on to purple and then blue with 11 additional drops....so I'm STILL getting 410....urgh!! But thanks for the suggestion! Another thing I know for sure....I'm running out of CH reagent...LOL
 
Re: Particles in the water seen only at night w pool lights

You could probably use a 10 ml sample size during your experimentation with different testing methods. Each drop would then be 25 ppm CH instead of 10 ppm CH. Since you know that you are near 400 ppm or so, you could add enough drops initially (before the calcium buffer and indicator dye) to get most of the way there, say to 350. That will hopefully make your endpoint more distinct. So 35 drops initially if using a 25 ml sample size or 14 drops initially if using a 10 ml sample size.
 
Re: Particles in the water seen only at night w pool lights

chem geek said:
You could probably use a 10 ml sample size during your experimentation with different testing methods. Each drop would then be 25 ppm CH instead of 10 ppm CH. Since you know that you are near 400 ppm or so, you could add enough drops initially (before the calcium buffer and indicator dye) to get most of the way there, say to 350. That will hopefully make your endpoint more distinct. So 35 drops initially if using a 25 ml sample size or 14 drops initially if using a 10 ml sample size.

I get it now...thanks to you both! Will test again in the am. I am very appreciative to everyone's comments and suggestions as always!

Laura
 
Re: Particles in the water seen only at night w pool lights

Today's CH test score = 430

I ran out of the R-0010 and R-0012 reagent that came with my TF-100 kit yesterday and had to run to Leslie's to pick up some more. ANY chance I rec'd aged reagent with my kit originally and if so....would that affect the test results at all? Regardless, it still shouldn't show that significant of a decline, yes?

FC - 7 (down 1ppm OCLT)
CC - 0
TC - 7
pH - 7.5
TA - 70
CYA - 60
CH - 430 (kept getting 410 all day yesterday and using my original bottle of reagent, today's test was done with brand new reagent)
CSI - neg 0.4
 
Re: Particles in the water seen only at night w pool lights

ika674,

You are overthinking the CH issue. CH typically does not change hardly at all.

I cannot explain why yours did so dramatically but most folks test CH once a month or so and that's good enough.

You are fine accepting it as 425 or so (plus or minus 25 is just fine....you can use a 10ml sample and use less reagent)

It will probably stay there the rest of the summer unless you add some or dilute your pool by a great deal.
 
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