Should a sand filter pick up everything?

zrtman

Bronze Supporter
Jun 7, 2022
33
Wilmington NC
Pool Size
6050
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
I have the dust like substance on the bottom of my pool. When I first noticed it I thought it was algae and tested my FC and CC and it was fine (3.5/0). Figured out it was like sediment (I do not know what else to call it).
Pool had not been used for 4 or 5 days and all this had just settled to the bottom. So I got the vacuum out and it comes off very easy..but then noticed the filter was not filtering it out - just recirculating back into pool. I did a back wash and flush still same result. (I am on correct setting for filter - I double checked). I did take valve off filter and sand must have settled since now it is below the minimum mark.

So my plan is to dump old sand and refill to max mark. But is there anything else I should be doing to help catch all the very fine dust (or whatever you want to call it)? You do not even have to brush it off - just fan the area with your foot and it comes off surface. If I remember correctly "clarifiers" are not good?

Pool has been super clean up until a week ago. Water extremely clear.

Thanks!
 
But is there anything else I should be doing
Since you are going to add sand anyways, I would recommend doing a deep clean of the existing sand before adding the new. Then after you add the new sand if the situation persists, do an Overnight Chlorine Loss Test to be sure it's not related to algae.

 
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Since you are going to add sand anyways, I would recommend doing a deep clean of the existing sand before adding the new. Then after you add the new sand if the situation persists, do an Overnight Chlorine Loss Test to be sure it's not related to algae.

I was actually going to dump the old sand and just add all new. Is that the same as a deep clean?
 
I have the dust like substance on the bottom of my pool. When I first noticed it I thought it was algae and tested my FC and CC and it was fine (3.5/0). Figured out it was like sediment (I do not know what else to call it).
Pool had not been used for 4 or 5 days and all this had just settled to the bottom. So I got the vacuum out and it comes off very easy..but then noticed the filter was not filtering it out - just recirculating back into pool. I did a back wash and flush still same result. (I am on correct setting for filter - I double checked). I did take valve off filter and sand must have settled since now it is below the minimum mark.

So my plan is to dump old sand and refill to max mark. But is there anything else I should be doing to help catch all the very fine dust (or whatever you want to call it)? You do not even have to brush it off - just fan the area with your foot and it comes off surface. If I remember correctly "clarifiers" are not good?

Pool has been super clean up until a week ago. Water extremely clear.

Thanks!
Your chlorine was down to 2.0 a week or so ago and 3.5 is barely above the minimum. You might check for algae more closely before going to the trouble with the filter.
 
I was actually going to dump the old sand and just add all new. Is that the same as a deep clean?
Sand typically never goes bad unless a pool store product like floc or clarifier was added to it. So a deep clean can fluff it up and break loose junk that may be imbedded. But if you wish to just replace it all we won't argue with you. Ha.
 
Sand typically never goes bad unless a pool store product like floc or clarifier was added to it. So a deep clean can fluff it up and break loose junk that may be imbedded. But if you wish to just replace it all we won't argue with you. Ha.
LOL well I have to buy a bag so I figured I would just dump it and start over lol
 
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Your chlorine was down to 2.0 a week or so ago and 3.5 is barely above the minimum. You might check for algae more closely before going to the trouble with the filter.
Yes good point. It had got too high so I was messing around with swg and then got it too low @ 2. Will do a overnight loss test tonight. Thank you!
 

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So been reading up and reading other posts. I am thinking I have mustard algae.

I watched this video and what I have 'poofs up' exactly like that. Except it is in an even layer on bottom and sides of pool. Or it was - I vacuumed the bottom and sides and brushed whatever was left. Now it is just suspended in the water - very cloudy. It is a yellow color - I assume that is why they call it mustard..


I did the over night test and FC dropped .5. But it also rained hard.. so not completely sure that is accurate. I checked it at 11pm and then 6am.

My cc is 0. Doing the tests with Taylor fas-dpd.

According to calculator for mustard I need to get FC to 34 (CYA of 60)?

Is there any easier way to test other than using an enormous amount of R-0871? Using the 10ml sample that is 68 drops..
 
You first pass all criteria for the SLAM Process.

Then, you follow the Mustard Algae FC level for 24 hours, ONLY.
Ok thank you for your response.

To be clear - I need to keep my FC at 24 (cya of 60) until pool clears up? My CC is zero and overnight loss is less than 1.

Once it is clear (water and walls/floor) I would then raise to the FC of 34 for 24 hours?
 
Ok thank you for your response.

To be clear - I need to keep my FC at 24 (cya of 60) until pool clears up? My CC is zero and overnight loss is less than 1.

Once it is clear (water and walls/floor) I would then raise to the FC of 34 for 24 hours?
Correct.
With passing OCLT, it is odd you have that much debris. But those little sand filters really struggle to pick it up. I doubt you have Mustard Algae.
 
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Also what could have caused this? Normally my FC is 4-4.5 (SWG and CYA of 60). It did get to 2.0 once - I purposely turned off swg because FC was too high after a week of cloudy/rainy weather.

We did have a storm come through one night that left a ton of pines needles floating in pool but FC was 4.

Also neighbor has used pool and brings pool floats that they use in the river and Intracoastal waterway. I did read an article that you can get it from stuff like this? One of the items they use is a large mesh bean bag type float.

Do I need to sanitize our pool floats, etc?

Sorry for all the questions... this is a learning experience.
 
Correct.
With passing OCLT, it is odd you have that much debris. But those little sand filters really struggle to pick it up. I doubt you have Mustard Algae.
I did read an article on here about adding a small amount of DE to the sand filter. I was thinking about trying that. When I was vacuuming it off the floor you could see some of it come right back out the return and into pool.

Ignorance is bliss I guess. I thought the sand filters were the way to go.
 
Sand filters work well, but the tiny ones that come with the ABG pool combos are just overwhelmed by even the tiny pump you have. You can try DE. but I suspect it will either plug quickly, or get blown into the pool.

You can try vac to waste, using a siphon. Some others have success with that in small ABG pools.
@Mdragger88
 
Also what could have caused this? Normally my FC is 4-4.5 (SWG and CYA of 60). It did get to 2.0 once - I purposely turned off swg because FC was too high after a week of cloudy/rainy weather.

We did have a storm come through one night that left a ton of pines needles floating in pool but FC was 4.

Also neighbor has used pool and brings pool floats that they use in the river and Intracoastal waterway. I did read an article that you can get it from stuff like this? One of the items they use is a large mesh bean bag type float.

Do I need to sanitize our pool floats, etc?

Sorry for all the questions... this is a learning experience.
With a CYA of 60 now, your bare bottom FC number 4ppm. Keep it closer to 8ppm so that if something happens and you lose 4ppm, it’ll still be above the minimum.

Curious what you thought was high chlorine? If it was over 10ppm, it wasn’t a problem except that the pH test starts to become inaccurate at that level.
 
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With a CYA of 60 now, your bare bottom FC number 4ppm. Keep it closer to 8ppm so that if something happens and you lose 4ppm, it’ll still be above the minimum.

Curious what you thought was high chlorine? If it was over 10ppm, it wasn’t a problem except that the pH test starts to become inaccurate at that level.
I was following what pool math was telling me. With a CYA of 60 it suggested a minimum of 3 and target of 4 (SWG). Normally on sunny days it hits 4.5 at the lowest. But was up to 11 after days of cloudy and cooler weather. Daughter is somewhat sensitive to chlorine so I was letting it drop back down by reducing run time on swg. Did not mean for it to get to 2 but honestly I thought as long as it was not zero I am still ok (I am a rookie lol).

I check FC in the morning before the swg's turn on so it is at it's minimum. Still learning here. I have to say it is pretty interesting.
 
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I was following what pool math was telling me. With a CYA of 60 it suggested a minimum of 3 and target of 4 (SWG). Normally on sunny days it hits 4.5 at the lowest. But was up to 11 after days of cloudy and cooler weather. Daughter is somewhat sensitive to chlorine so I was letting it drop back down by reducing run time on swg. Did not mean for it to get to 2 but honestly I thought as long as it was not zero I am still ok (I am a rookie lol).

I check FC in the morning before the swg's turn on so it is at it's minimum. Still learning here. I have to say it is pretty interesting.
Gotcha, that 3ppm is really only for someone who’s got things super dialed in well. I don’t trust the lower recommendations for SWG.

It’s very likely your daughter isn’t sensitive to chlorine but chloramines which are more typically found in undersanitized water that’s actively oxidizing things in the water. Give it a try once your water is stabilized.
 

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