What's wrong with my pool filter?

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beeza

Guest
My pool is going cloudy. I get a build up of algae on the bottom. If I vacuum in filter mode, I see all the gunk I've vacuumed off the bottom pump straight out of the jets back into the pool.

I thought that perhaps it was because the sand in my filter was around five years old. I replaced the sand, but it's still the same.

Even if I leave the pump running for some time with the cloudy water, it doesn't clear. I even tried doing a backwash, and the water coming out through the sight glass is clean.

What could be wrong?
 
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cobraboy

Guest
First place I would look is your diverter valve on the filter. I will be it is either broken, the gasket is bad (if it is a gasket model) or the seal between the moving valve parts have sand or grit in them, allowing gunk to escape back into the outlet.

None of these are particularly disasterous or expensive problems. You can do this yourself with your mechanical background.

Another area of possible problems is whoever replaced the sand damaged the filter vanes. Very common occurance, because age can make the vanes brittle. Some systems have a mesh bag over the vanes (usually with DE filters), some don't. This is a slightly more complex problem because you have to remove the sand to get to the vanes.

I have been there not long ago.
 
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cavok

Guest
Check the pressure guage on your filter. After backwashing, it should read around 10 psi. If it's less than "normal"(ie, after backwashing when new), water might be going back out the diverter valve as CB said. It depends on how bad the leakage.

To take care of the cloudy water, you first need to super chlorinate the pool and then use a flocculant to remove fine suspended particles that are too small for the filter to remove.

DE filters are much better than sand filters and cost less. They're able to filter out much smaller particles than sand filters. There's the additional cost of DE powder, but it's not very expensive. Very common in Florida, but I don't see too many here.
 
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windeguy

Guest
The dust from Africa which enters our pools cannot be easily trapped by a sand filter. It is an extremely fine powder.

A DE filter can probably trap it, but they don't frequently sell them here because maintenance is a delicate issue. Any time you use the word delicate in this country, and you would get my idea as to why they are rare.

All the other suggestions are valid places to look. I also replaced my sand thinking it would help. I found no breaks in the filter vanes, and had a new diverter, etc. and it did not filter any better than it did before. I just vacuum to waste to fix the problem. In my case if the water is a little cloudy, I just wait a day or two and it settles to the bottom and vacuum to waste.
 
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Cdn_Gringo

Guest
I agree with cavok.

1) Confirm filter is working properly.
2) Backwash and rinse your filter - may as well start off as clean as you can get it.
3) Add water to a level a little higher than you normally keep it at.
4) Add 1/2 bag/canister of chlorine granules (not pucks) to the skimmer and run filter for at least three hours. Close the floor drain and just use the skimmers for this part.
5) Shut filter off and let particles sink to the floor for at least 12 hours.
6) Slowly so as not to stir up dead algae, vacuum to WASTE the floor of the pool first and then the sides.
7) Add water to replace that which was removed by the vacuuming to a level higher than normal.
8) Test water and adjust levels accordingly. Chlorine levels should still be high and that's ok.
9) Run filter as you normally do. Should be no more swirling gunk on the floor after 24 to 36 hours.

Vacuum to WASTE every day until there is no more gunk. After a couple of days, decide if you wish to use a floc to further clear up the water. Always vacuum that to waste after 12 to 15 hours of settling with no filter or pool use during that settling time.

Let water level return to normal and wait for the chlorine levels to drop back to normal before adding more. No problem if you wish to have a chlorine puck floating around while you wait.

If your filter equipment is not broken, this is almost certainly an algae bloom. You should not be vacuuming floc and heavy algae particulate through your sand in filter mode - you need to get that completely out of the system by using the filter's waste & rinse settings.
 
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cobraboy

Guest
I use 1 micron diesel fuel filters attached to the pool outlets to trap the tiniest of particles the sand filter cannot

I have also switched to chlorine tablets that have chlorine, algaecide and clarifier. I had no algae problems at all since the switch, and in conjunction with the bag filters the pool is always crystal clear.

I agree with C_G: if you do have algae, raise the water level as high as possible, and vacuum the pool with the water going to waste.

As a side note, a strong dose of clarifier will coagulate the algae into larger particles and make filtering more effective.

I have not seen DE in the DR. Does it exist? A DE filter is definitely the most efficient.
 
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windeguy

Guest
Yep, wait for it to settle and vacuum to waste.

I have not seen a DE filter here either. You could import one and probably would cost less than buying it here if you found the only one for sale. American Pool supply on the Cabarete/Sosua highway does sell DE powder.

The only chemical I have used for years in my pool is granulated trichlor.
(Remember the pool boy from Canada that used to post on DR1? He told me there was no such
thing as granulated trichor after I had been using it for years. There was a time that regular chlorine granules were not available years ago and I switched to the trichlor.)
 
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malko

Guest
I also do the vacum to waste trick...... but it is annoying to lose so much water every time.... oh well.
 
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chico bill

Guest
My pool is going cloudy. I get a build up of algae on the bottom. If I vacuum in filter mode, I see all the gunk I've vacuumed off the bottom pump straight out of the jets back into the pool.

I thought that perhaps it was because the sand in my filter was around five years old. I replaced the sand, but it's still the same.

Even if I leave the pump running for some time with the cloudy water, it doesn't clear. I even tried doing a backwash, and the water coming out through the sight glass is clean.

What could be wrong?
When is the last time you painted your pool ?
Is is a darker color paint ?
Once the paint begins to oxidize it will deposit particles in the water and turn your feet the color of the paint.
Start with back-washing the sand filter to waste (close off the skimmer and pump from the bottom) to avoid cavitating the pump).
Then after washing for 10 minutes, refill pool to over the skimmer and then use an aluminum phosphate to flocculate the pool (scatter around the pool liberally and let the pumps run an hour (Shut pumps and insure they do not come on again breaker off) of and give it a day.
Then before it gets windy, vacuum the bottom (to waste) with the skimmer valve closed again.
This will clear the pool. But it it is the paint oxidizing it won't be clear long
Drain and repaint with two part epoxy paint (and use lighter blues or even a new white that takes a bluish tint under water)
10,000 gallon pool takes about $250 to repaint (not counting your labor) after using muratic acid diluted in a garden sprayer to first clean and wash down old paint
 
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cavok

Guest
When is the last time you painted your pool ?
Is is a darker color paint ?
Once the paint begins to oxidize it will deposit particles in the water and turn your feet the color of the paint.
Old oxidizing paint could very well be the problem. The filter won't remove that.

Vacuuming to drain is ok if you only do it once in a while, otherwise you're upsetting the water balance and increases the need for chemicals.
 
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windeguy

Guest
Old oxidizing paint could very well be the problem. The filter won't remove that.

Vacuuming to drain is ok if you only do it once in a while, otherwise you're upsetting the water balance and increases the need for chemicals.
I vacuum to drain all the time. Then I add trichlor. Only trichlor. Done it for years.
Repainting is done every five years or so.
 
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beeza

Guest
When is the last time you painted your pool ?
Is is a darker color paint ?
Once the paint begins to oxidize it will deposit particles in the water and turn your feet the color of the paint.
Start with back-washing the sand filter to waste (close off the skimmer and pump from the bottom) to avoid cavitating the pump).
Then after washing for 10 minutes, refill pool to over the skimmer and then use an aluminum phosphate to flocculate the pool (scatter around the pool liberally and let the pumps run an hour (Shut pumps and insure they do not come on again breaker off) of and give it a day.
Then before it gets windy, vacuum the bottom (to waste) with the skimmer valve closed again.
This will clear the pool. But it it is the paint oxidizing it won't be clear long
Drain and repaint with two part epoxy paint (and use lighter blues or even a new white that takes a bluish tint under water)
10,000 gallon pool takes about $250 to repaint (not counting your labor) after using muratic acid diluted in a garden sprayer to first clean and wash down old paint
The pool has a glass tile floor and diamond brite walls. An investment I made some time ago that has paid off. Since doing that, I needed few little chemicals to keep it pristine.

This is a recent problem and it looks like the filter. I might have to take the filter head apart to check the gaskets or empty the sand and check the spider at the bottom.

But I'm not sure that if one the spider's legs was broken, would it pump sand into the pool?
 
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cavok

Guest
I vacuum to drain all the time. Then I add trichlor. Only trichlor. Done it for years.
Repainting is done every five years or so.
Trichlor is good. I've used it. Vacuuming to drain will cause you to use more chlorine than otherwise, though, and the chlorine level will fluctuate.
 
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cavok

Guest
The pool has a glass tile floor and diamond brite walls. An investment I made some time ago that has paid off. Since doing that, I needed few little chemicals to keep it pristine.
We called that "marcite" in Florida. Much better than epoxy paint. After ten years, my pool still looked great.
 
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cobraboy

Guest
We called that "marcite" in Florida. Much better than epoxy paint. After ten years, my pool still looked great.
When the original marcite in my pools in FL needed renewal, I had the pools lined with fiberglass and gelcoat. Excellent solution.

Chemical consumption dropped like a rock.
 
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cavok

Guest
When the original marcite in my pools in FL needed renewal, I had the pools lined with fiberglass and gelcoat. Excellent solution.

Chemical consumption dropped like a rock.
I've heard of that and they say it works great.
 
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cobraboy

Guest
I've heard of that and they say it works great.
My only criticism, and the same criticism I make about epoxy pool paint, is the floor becomes very slippery on bare feet, and I have to use water shoes for traction.

Of course, this is why algae won't grow on it: nothing to adhere to.
 

sosuadr

Member
Aug 17, 2014
21
0
6
cobraboy was right, beeza, and a few others too. Take the 5 of 6 screws off the top of your valve and you will find the gasket underneath it is likely deformed/broken. easy fix.