Sand filter failure

[Old Eagle]

My pool water won't clear. I used a filter cleaner and I have used clarifier multiple times bu the water is not clear. It used to be clear after only 2 or 3 days of continuous filtration.

Is it time for new sand?

[Anonymous [GDPR] European in the UK]

Old Eagle, new sand is a hoax, it turns out to be just as old as the old sand well +/- a million years or two.
Sand doesn't wear out in sand filters because it's stationary for most of it's working life, it get dirty, bio fouled stuck together and therefore channeled.
The channels allow free un filters passage which is your problem sounds like.
The cleaner you used may not have done the whole job and I have noticed just how bad domestic filters can backwash. In one case we removed the media into dustbins and thoroughly cleaned it before putting the same media back which is now once again perfect.

[CarlD]

It's hard to diagnose. First off, the clarifier may well have gummed up your sand, in which case the cheapest and easiest solution is replacement. Teapot's right about the channeling.
Other things are that your filter may be too small for your pump's horsepower, or you have damaged laterals (internals of the filter).

Sand doesn't wear out, and, in fact, a well-tended sand filter tends to filter BETTER as the sand gets older. The hard-edged points on "new sand" get worn down and it packs closer trapping more dirt. My sand is in its 13th season and just getting better and better.

But without knowing the size and capacity of your pool, filter and pump, it's hard to diagnose.

[Old Eagle]

I am willing to try cleaning the sand but don't know what to do. I put in a good amount of laundry detergent and left it for 2 hours and then backwashed it out but the filtration still is nothing. Even though the pool is now quite cloudy, the filter back pressure has not gone up in 6 hours of running. You spoke of channeling. How do I undo that? Maybe I should replace the sand. This is stopping a lot of swimming.

[CarlD]

Laundry detergent? No, no, no, no, no! Now I believe you MUST replace the sand (I could be wrong). You may have too little sand as well. Or your filter may have been loaded with sand-blaster sand, rather than pool filter sand.

Changing sand isn't too hard and 50lb bags of pool filter sand are usually less than $10. You'll need to know how much your filter takes: 150 lbs, 200lbs, 250lbs, etc.
You'll have to disconnect and remove the top. If it's a top-mount filter, the whole multi port valve comes off. A side mount valve filter may be different.
You'll need to scoop out the old sand. The tricky part is the laterals, the internal plumbing that looks like an upside-down umbrella. You don't want to damage that as you dig out the sand. Once the laterals are clear, you fold them in (like an umbrella) and lift them out. You'll need to inspect them for damage and replace any damaged ones. Dump out the rest of the sand.

When you are satisfied the laterals are fine, you'll start putting new sand in the filter. There will be molded-in rests for the laterals. Do NOT cover these with sand. Just sand below them. Then put in the laterals, unfold them, and seat them, making sure each is in its rest. Now GENTLY add more sand to cover them, being careful NOT to pour sand down the vertical pipe--Masking tape can cover it for now. Duct tape may stick. Add sand evenly until you've reached the capacity of the filter, and gently level it off. You can pour in clean water to help the sand level, but you DON'T want it moving the sand around.

Before you reinstall the multi port valve, check to see that it's working correctly, that the "spider gasket" isn't damaged, and the O-ring that goes around the valve is good, too. Then you can reconnect it all.
You'll want to run the filter on "Rinse" then "Backwash" before going back to "filter".

However, I asked before and I'll ask again: What is the size of your pump and filter? If your pump is too powerful for your filter, this is all a waste of time. You'll need a bigger filter or a less powerful pump.

Best I can do on limited info.

[Anonymous [GDPR] European in the UK]

Yep as Carl said, laundry detergent, loaded with phosphates! I hope a teaspoon of that didn't make it back into the pool.
It's always a good idea to fill the filter half full of water before commencing a fill. It not only reduces the amount of dust you may breath in but it slows down the impact of the sand on the laterals. Personally I would add course gravel to cover the laterals before the sand goes in.

Backwash the new sand and then rinse....before filtering

[CarlD]

I would only add gravel if the owner's manual calls for it. Otherwise, follow the manual. Pool sand should not be very dusty anyway. Half full with water sounds like a lot to me, but I don't suppose it would hurt. I prefer just adding sand slowly and gently. What's the rush?

[Old Eagle]

Old Eagle, new sand is a hoax, it turns out to be just as old as the old sand well +/- a million years or two.
Sand doesn't wear out in sand filters because it's stationary for most of it's working life, it get dirty, bio fouled stuck together and therefore channeled.
The channels allow free un filters passage which is your problem sounds like.
The cleaner you used may not have done the whole job and I have noticed just how bad domestic filters can backwash. In one case we removed the media into dustbins and thoroughly cleaned it before putting the same media back which is now once again perfect.

I am willing to try pulling the sand out and cleaning, but what did you do to clean it?

[CarlD]

You cannot clean it out of the tank if you cannot clean it in the tank. Isn't that clear?

I feel like you are not reading the comments all the way through, and only reading what you want to read.

Please remember: The final choices and responsibility for your pool rest with you and nobody else.
I wish you the best of luck.

[Old Eagle]

Carl, I do read all of the messages that try to answer my questions. I was trying to ask Teapot about his statement. It was : "In one case we removed the media into dustbins and thoroughly cleaned it before putting the same media back which is now once again perfect." So I wanted to know what he did to clean the sand. My sand is certainly pool sand, and it worked fine for about 4 years and then stopped filtering. I have just tried Leslie's "Pool Sand Revitalizer" and it has done nothing. I am ready to change the sand, but I am physically disabled so that will be time consuming. The expense is not what bothers me or made me seek a way to clean it in place..

My filter is a Hayward top fill type. Have you got any suggestions on the best way to remove the sand? I will try to fashion a scoop that is small enough to go down into the filter. The center pipe is a hindrance and I know to not let sand get in it, so I will plug it.

[BJohnston]

Old Eagle,

I just replace my sand this year at the start of the season. Last year I had problems with sand coming back thru returns which I always noticed on my steps. I inherited my pool and all equipment when I bought my house 2 years ago so I didn't have a good idea of the history of maintenance done. I suspected there was a broken lateral, or worse yet, that they hadn't used the correct sand.

What I found out was that my laterals and everything was fine, not broken or cracked, and that they indeed used the correct sand. I also replace the entire top multi port gasket as mine was so cracked and repaired that it was a time bomb ticking and $30 in replacement gaskets would be worthless if it failed, so I bit the bullet and got a new one for about $70. I suspect this was the cause of my sand issues as I have no clue what else could have been the cause. Replacing the sand was probably not needed in my case, but I'm glad that I did. I now know exactly whats in there and what chemicals and gunk has been put thru it, which is nothing but the BBB things. No clarifier, No magic sauce or pool store suggestions.

I understand that you are disabled so it might not be easy for you to do, but if your going to take the time to do yourself, or hire someone, to empty out the sand to clean it, you might as well just get brand new, considering the time and energy it would take to clean, if that's even possible, and also the fact that it seems that you have introduced a lot of gunk into it that's not great for your water chemistry.

My top load hayward S 210 called for 200lbs of sand, or (4) 50lb. bags. @ $12 per bag ~$48 + tax from my local store. It was pretty straight forward to dump and replace. I can't seem to find the manual for your filter online so I don't have a clue of its recommended capacity, but it should be listed on the side of the filter tank somewhere.

Given everything your sand has been thru, and the time/energy to take it out to clean, it might be more cost effective to just replace with fresh new stuff. But then again I don't know how much new will cost you, or if it would even be in your budget. I would look into it though. Maybe you can find some great neighbors to help you, and offer some swim time in exchange for helping?

One thing for after you get your sand figured out, there has also been discussion on here about using a very small dose of DE (diatomaceous earth) thru sand filters to help filter out all the fine small stuff that might otherwise get by. Just do a search on here for it or a google search. I have used it with success to help get my water crystal clear. I would strongly suggest reading up a lot on it before trying it though. Its not difficult to do, but you need to know the steps and what your doing so you don't cause more problems.

~BJ

[CarlD]

Carl, I do read all of the messages that try to answer my questions. I was trying to ask Teapot about his statement. It was : "In one case we removed the media into dustbins and thoroughly cleaned it before putting the same media back which is now once again perfect." So I wanted to know what he did to clean the sand. My sand is certainly pool sand, and it worked fine for about 4 years and then stopped filtering. I have just tried Leslie's "Pool Sand Revitalizer" and it has done nothing. I am ready to change the sand, but I am physically disabled so that will be time consuming. The expense is not what bothers me or made me seek a way to clean it in place..

My filter is a Hayward top fill type. Have you got any suggestions on the best way to remove the sand? I will try to fashion a scoop that is small enough to go down into the filter. The center pipe is a hindrance and I know to not let sand get in it, so I will plug it.

Yes. Use a garden trowel, particularly if you can find one with a rounded, rather than a pointed tip. Be patient. Not sure, but I think each bucket of dry sand is about 45-50 lbs. Wet sand is far heavier. In my pool rebuild I brought in 4 1/2 yards of sand. I shoveled every blessed shovel-full of it, the last yard by myself, and up a ramp and staircase. I learned the hard way there are 40.4 buckets to a yard......

If you are disabled, then realize that trying to remove and clean the sand is twice the work of simply removing and replacing it. Top mounts are actually easier to work.

[Old Eagle]

Old Eagle,

I just replace my sand this year at the start of the season. Last year I had problems with sand coming back thru returns which I always noticed on my steps. I inherited my pool and all equipment when I bought my house 2 years ago so I didn't have a good idea of the history of maintenance done. I suspected there was a broken lateral, or worse yet, that they hadn't used the correct sand.

What I found out was that my laterals and everything was fine, not broken or cracked, and that they indeed used the correct sand. I also replace the entire top multi port gasket as mine was so cracked and repaired that it was a time bomb ticking and $30 in replacement gaskets would be worthless if it failed, so I bit the bullet and got a new one for about $70. I suspect this was the cause of my sand issues as I have no clue what else could have been the cause. Replacing the sand was probably not needed in my case, but I'm glad that I did. I now know exactly whats in there and what chemicals and gunk has been put thru it, which is nothing but the BBB things. No clarifier, No magic sauce or pool store suggestions.

I understand that you are disabled so it might not be easy for you to do, but if your going to take the time to do yourself, or hire someone, to empty out the sand to clean it, you might as well just get brand new, considering the time and energy it would take to clean, if that's even possible, and also the fact that it seems that you have introduced a lot of gunk into it that's not great for your water chemistry.

My top load hayward S 210 called for 200lbs of sand, or (4) 50lb. bags. @ $12 per bag ~$48 + tax from my local store. It was pretty straight forward to dump and replace. I can't seem to find the manual for your filter online so I don't have a clue of its recommended capacity, but it should be listed on the side of the filter tank somewhere.

Given everything your sand has been thru, and the time/energy to take it out to clean, it might be more cost effective to just replace with fresh new stuff. But then again I don't know how much new will cost you, or if it would even be in your budget. I would look into it though. Maybe you can find some great neighbors to help you, and offer some swim time in exchange for helping?

One thing for after you get your sand figured out, there has also been discussion on here about using a very small dose of DE (diatomaceous earth) thru sand filters to help filter out all the fine small stuff that might otherwise get by. Just do a search on here for it or a google search. I have used it with success to help get my water crystal clear. I would strongly suggest reading up a lot on it before trying it though. Its not difficult to do, but you need to know the steps and what your doing so you don't cause more problems.

~BJ

BJ, Thanks for all your comments. I am replacing the sand. It has arrived this evening. I will replace it tomorrow. I have fashioned a little scoop from a plastic bottle and it just fits past the center pipe. I have taped the center pipe so I won't get sand in it.

Thanks again for all your message.

Old Eagle

[Old Eagle]

BJ, Thanks for all your comments. I am replacing the sand. It has arrived this evening. I will replace it tomorrow. I have fashioned a little scoop from a plastic bottle and it just fits past the center pipe. I have taped the center pipe so I won't get sand in it.

Thanks again for all your message.

Old Eagle

[Old Eagle]

I ended up getting my big shop vacuum and using it to pull the old sand out. I was careful to not suck up too much wet sand at a time before emptying the shop vac. It could hold 50 or 60 pounds but I would not be able enough to dump it out. Anyway, I got the sand all out in a fairly short time.

I cut up a bleach bottle to make a scoop to get the new sand out of a bag and I scooped sand out of the 50 pound bag until there was about 15 or 20 pounds left in the bag and then I lifted the bag and poured. Yes, I had tape over the center pipe opening. I put about a foot of water in the filter tank before starting to pour the sand in.

With all 250 pounds of sand in the filter tank, I put the top valve assembly back on, switched the valve to backwash and started the pump. When the view glass seemed completely clear, I switched to filtering, and now a lot of filtering and Kreepy Krauly work has to be done as I had killed off some green algae and the pool bottom was coated dark green.

Now I have a question. I am considering putting a liquid cover on the pool to help it save heat. Is that stuff going to foul the filter? Perhaps I shouldn't use it? Please CARL and any others, what do you think?

[Watermom]

The consensus around here is a big NO. Don't use the liquid cover on your pool.

[CarlD]

The consensus around here is a big NO. Don't use the liquid cover on your pool.

Exactly. Get a lighter cover (12 mil) and a cover reel. You'll be much happier.

[Old Eagle]

I believe you on the NO for the liquid cover. I can imagine it fouling the sand. Thank you both Watermom and Carl.
Another question: What about the idea of putting a limited amount of DE media on top of the sand in my sand filter? I have not done this, but it sounds logical when you think of the very fine particles that cloud a pool and keep going through the sand filter. In past years I did have good results using a clarifier solution to make the fine particles stop going through the sand filter. Now I am scared of adding anything but bleach and chemicals to adjust the PH.

[CarlD]

Both WaterMom and I, and many others have added DE and the results are excellent.
Record your pump's pressure (on high if a 2 spd or VS) apnd keep it running.
Add 1/4 cup of DE and wait 20 minutes.
Wait, oh 20 minutes and see if the pressure has increased by 1pound, if so you are done. If not, add another quarter cup and wait again repeat until you reach one pound increase in preassure.
If you go over more than two punds, just backwash it out and start again. Try 1/3 cup this time.
Once you find the right amount, which will be between 1/4 cup and one cup, just add that much everytime after you backwash.

That's all there is to it!

[Old Eagle]

Thanks much! That sounds like a very good plan. I had not thought about the backwash pulling the DE out but I guess that really will remove it. I am guessing that you put the DE in at the skimmer, but maybe at the pot just before the pump. I suppose either will work and the skimmer would be easier.

[CarlD]

No, no, it MUST be in the skimmer while the pump is running! You have to shut down the pump and shut off valves to open the pump's skimmer pot. Then it probably will clog and not distribute properly.
Don't make things tougher on yourself than you need to!

[Old Eagle]

Carl, Thanks again for all your very good advice.

[Old Eagle]

Carl,
Your advice on how to use some D.E. in the sand filter works great. The cloudy stuff in my pool is being caught at a high rate. I had to use a fairly large amount of the D.E. to get the 1 pound rise in pressure you suggested. I think that is because my filter has a large amount of surface area which needs a coating to get the pressure rise. That surface area is about 1000 square inches.

One certainly does not need a water clarifier when you use your D.E. method.

I have noticed an interesting thing happening so I will report it here. When I put in the D.E., check the pressure, and then start up my Kreepy Krauly, I think the pulsations of the Kreepy Krauly cause the D.E. to disappear, probably passing right on through the sand and back into the pool. The small amount of D.E. would not be noticeable in the pool if that is what happens. It may be that the D.E. disappears because I have a yet-to-be-found air leak in the return line that causes the filter pump to sort of cycle up and down in pressure as it grabs the air and then grabs more water. I have yet to locate the return line leak but I know how to do that and will fix the leak as soon as I do.