trouble venting air from DE filter.....questions

anthony21078

Well-known member
Jun 14, 2018
90
Long Island NY
Just had my local pool store install install a new Hayward MaxFlo VS 500 pump to pair up with my existing Hayward DE3620 filter. The tech was there only to install the pump and get the system started. I decided to go with the local purchase instead of buying online since the price after the rebate from the electric company was same, the warranty is extended to 3 years, and the electric company wont honor the rebate unless purchased and installed from a specific list of local retailers. A few days prior I opened the filter and completely cleaned the grids. I inspected the best I could and did not see any rips on the grids and no cracks on the manifold.

So after the pump was installed, the tech started it up and we dumped the 4.5lbs of DE in the skimmer. The returns were clear and no DE was coming back into the pool. I recall the tech going back to the filter, cracking the air relief valve and after a minute or two, steady water was coming out and he closed the valve. After that he was on his way.

I just opened the pool yesterday and the water is clear but there was a lot of dirt and leaves on the floor. I turned the pump off, setup the vacuum and vacuumed to waste (took about 45 min to vacuum). I had to empty the filter basket twice because it was full. I decided to backwash about 2 minutes (which was unnecessary but I wanted to play with the pump settings), kill the pump, switch to rinse for 20 seconds, kill the pump then switch to filter and proceed with adding new DE (straight from the Hayward filter manual). Again, no DE was coming through the returns.

So I tried to vent the air from the filter 2 ways (first keeping the valve open before starting the pump and second, keeping the valve closed before starting the pump) and both times after the air has vented, I did NOT get a steady stream of water ONLY. But rather a slurry of DE water coming from the vent. But no DE is coming out the returns. When the slurry water/DE mix comes out the vent and I attempt to close the valve, the DE builds up in the threads and I cant get valve to seat properly which causes air to leak out. Why am I seeing DE coming out the valve?

Some questions.....
1)What is the right way......Are you supposed to have the air relief valve open or closed before you start the pump when adding new DE?

2)I'm under the impression that every time you open the system you should bleed of the air? Is this correct?

3)These are the pump settings the tech setup.
Timer 1
8:15a to 9:15a 7 days 2925rpm
Timer 2
6:15p to 7:15p 7 days 2925rpm
Timer 3 (I dont feel any water coming out the returns)
12:00am to 11:00pm 7 days 1000rpm

Is this sufficient?

4)I have yet to see the pump completely fill with water. On the low setting the the filter basket barely has any water in it. When I manually switch the pump to the high speed, the filter basket is never completely full but the stream of water coming out the returns is very strong. I recall my previos pump was always full with water.

Thanks

98905
 
Last edited:

anthony21078

Well-known member
Jun 14, 2018
90
Long Island NY
This is what the filter basket looks like after priming for 3 minutes and running at 3175 rpm for 30 minutes. The water level is just below the top of the basket. Filter pressure is 14psi



This is what the filter basket looks like after priming for 3 minutes and running at 1250 rpm for 30 minutes. The water level is just below the bottom of the suction pipe. Filter pressure is 1 psi

 

duraleigh

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Apr 1, 2007
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Sebring, Florida
I am not a DE expert so I'll let others help with that. However, the very clear video you provided show a suction side air leak that I think you need to find and fix first. At 3150 rpm, a properly sealed system will have NO bubbles whatsoever.......air is being sucked into your system somewhere from the skimmer(s) to the pump strainer basket.

There is an article in Pool School that goes into some detail and may help you find the leak.

Unscrew that grey union and make sure the O-ring is installed in there. missing O-rings are a common source for that type leak.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,921
San Dimas, CA (LA County)
I think you need to be patient. Let the DE that's all mixed up with the water coat the grids before you release the air. Then you'll just get water out. I don't recharge mine but maybe twice a year at most, so it's been awhile, but I can't recall ever seeing anything come out. When the bubbles disappear from the pump basket and it stops farting out the returns and the pump has settled into a nice steady hum, I bleed any trapped air.

You need to hunt for the source of your air leak. Most common is low water level in the pool so that a vortex is created in the skimmer. Next most likely is the weir is stuck so the skimmer level is lower that the pool and you suck air. Then you look at drain plugs on the pump, pump lid gasket, unions, three way valve stem seals, and the rest.

One final thought.... I wonder if the tech somehow messed with the air bleed inside the filter? It's a long tube with a plastic end on it that contains a fine mesh screen. It just flops around inside and it's supposed to be positioned up alongside the grids somewhere so that the end is at the top. I wouldn't tear it apart just to see, but do look for that the next time you have it opened up. It's on the pressure side, so it will have nothing to do with the basket full of air, but it might contribute to DE spitting out.
 

anthony21078

Well-known member
Jun 14, 2018
90
Long Island NY
I am not a DE expert so I'll let others help with that. However, the very clear video you provided show a suction side air leak that I think you need to find and fix first. At 3150 rpm, a properly sealed system will have NO bubbles whatsoever.......air is being sucked into your system somewhere from the skimmer(s) to the pump strainer basket.

There is an article in Pool School that goes into some detail and may help you find the leak.

Unscrew that grey union and make sure the O-ring is installed in there. missing O-rings are a common source for that type leak.
Here comes the novice in me....Does a suction side air leak mean the air has to be coming from either the pump or the plumbing before the before pump? Could air be entering the system somewhere after the pump? I ask because now that you said that, the tech yesterday stated he thought he felt air getting pulled in from the backwash port momentarily after the initial startup but dismissed it after the pump was running.

I will check that grey union soon

I think you need to be patient. Let the DE that's all mixed up with the water coat the grids before you release the air. Then you'll just get water out. I don't recharge mine but maybe twice a year at most, so it's been awhile, but I can't recall ever seeing anything come out. When the bubbles disappear from the pump basket and it stops farting out the returns and the pump has settled into a nice steady hum, I bleed any trapped air.
Ok so Ill let the system run for a day or 2 and try to bleed again. BUT, in the filter manual it almost reads like the valve is supposed to be open prior to startup and adding new DE. Nevertheless, I suppose you can bleed anytime you want also.

You need to hunt for the source of your air leak. Most common is low water level in the pool so that a vortex is created in the skimmer. Next most likely is the weir is stuck so the skimmer level is lower that the pool and you suck air. Then you look at drain plugs on the pump, pump lid gasket, unions, three way valve stem seals, and the rest.
Water level is 3/4 to the top of the skimmer port. I just put new weir doors and they move freely. I can also see into both skimmers from the top and water is always high and moving when the pump is running on high

Like duraleigh suggested, Ill take a look at the grey union and also take apart the 3 way valve to inspect.

One final thought.... I wonder if the tech somehow messed with the air bleed inside the filter? It's a long tube with a plastic end on it that contains a fine mesh screen. It just flops around inside and it's supposed to be positioned up alongside the grids somewhere so that the end is at the top. I wouldn't tear it apart just to see, but do look for that the next time you have it opened up. It's on the pressure side, so it will have nothing to do with the basket full of air, but it might contribute to DE spitting out.
I was hanging around the tech basically the whole time watching and asking questions. He didnt even touch the filter. I dissablemed and re-assembled the filter myself the other day. The air vent your referring was sitting upright at the time I placed the lid on and secured it.

A few other things if needed. I have 2 skimmers, 1 main, and 2 returns. When I alternate the 3 way valve the pump to still wont fully prime regardless if it is pully water from the only the skimmers, the main or both.


9894698947
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,921
San Dimas, CA (LA County)
I'm thinking more like ten minutes rather than 2 days. :)

Air leak has to be before the pump impeller. Everything beyond that is pressurized. You would have water squirting out, not air sucking in. And since the leak doesn;t change depending on sources, your air leak is somewhere between the valve and the pump, inclusive.
 
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anthony21078

Well-known member
Jun 14, 2018
90
Long Island NY
I'm thinking more like ten minutes rather than 2 days. :)

Air leak has to be before the pump impeller. Everything beyond that is pressurized. You would have water squirting out, not air sucking in. And since the leak doesn;t change depending on sources, your air leak is somewhere between the valve and the pump, inclusive.
Lol I hear ya. I'll report back after I open the fittings
 

anthony21078

Well-known member
Jun 14, 2018
90
Long Island NY
Happy to report that the pump is operating properly. I opened the 3 way valve and cleaned/lubed the o-ring. I gave that grey union about a 1/4 turn with the wrench and now the pump basket is filled with only the tiniest of bubbles on all pump speeds.

 
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chiefwej

LifeTime Supporter
TFP Guide
Jun 12, 2011
3,504
Tucson
Each time the pump shuts down much of the DE falls off the grids into the bottom of the filter. When the pumps first starts back up it is picked up in a slurry and re deposited on the grids. If you open the air relief valve too early you get that slurry. Just wait a bit for things to settle down before bleeding any air. I have exactly the same filter but since my VS pump starts with its own internal timer each morning, I seldom get around to bleeding air out of the filter, and it has never seemed to be a problem.
 

anthony21078

Well-known member
Jun 14, 2018
90
Long Island NY
Each time the pump shuts down much of the DE falls off the grids into the bottom of the filter. When the pumps first starts back up it is picked up in a slurry and re deposited on the grids. If you open the air relief valve too early you get that slurry. Just wait a bit for things to settle down before bleeding any air. I have exactly the same filter but since my VS pump starts with its own internal timer each morning, I seldom get around to bleeding air out of the filter, and it has never seemed to be a problem.
That explains it. Thank you
 

Michael1

Well-known member
May 3, 2015
193
Moorpark, CA
Each time the pump shuts down much of the DE falls off the grids into the bottom of the filter. When the pumps first starts back up it is picked up in a slurry and re deposited on the grids. If you open the air relief valve too early you get that slurry. Just wait a bit for things to settle down before bleeding any air. I have exactly the same filter but since my VS pump starts with its own internal timer each morning, I seldom get around to bleeding air out of the filter, and it has never seemed to be a problem.
Maybe I have been lucky, but this has not been my experience. I've never had any DE come out of the vent. I have had small debris come out that got sucked out of the pool.

Couple of things come to mind. Have you checked your manual to see how much DE is required on a back flush? It is usually less than doing a full grid cleaning.

BEFORE I put any DE in the system, I vent first. I want the water level in the filter to be at the top, so the DE coats the entire grid.

I also mix the DE in a bucket of water, and then pour it into the skimmer intake. I also do this very slowly, and in stages, so it doesn't overload the line or the system.
 
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anthony21078

Well-known member
Jun 14, 2018
90
Long Island NY
Maybe I have been lucky, but this has not been my experience. I've never had any DE come out of the vent. I have had small debris come out that got sucked out of the pool.

Couple of things come to mind. Have you checked your manual to see how much DE is required on a back flush? It is usually less than doing a full grid cleaning.

BEFORE I put any DE in the system, I vent first. I want the water level in the filter to be at the top, so the DE coats the entire grid.

I also mix the DE in a bucket of water, and then pour it into the skimmer intake. I also do this very slowly, and in stages, so it doesn't overload the line or the system.
The manual calls this "pre-coating" and its always 4.5lbs whether you backwash OR open the filter and clean the grids.

As stated above, I was having air leak issues with my new pump and perhaps that was contributing to the problem of the DE coming out the filter. I'm not sure.......but now since the pump is operating correctly with no air in the basket (and I haven't opened the system since its been running properly), only water comes out the air relief valve. No DE and no air
 

chiefwej

LifeTime Supporter
TFP Guide
Jun 12, 2011
3,504
Tucson
When you do a full breakdown cleaning, use the full amount of DE. If you back flush without tearing down the filter, only use 80% of the listed DE charge.
 
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Frank1026

In The Industry
Jun 23, 2017
14
Stockton, CA
I'm curious as to why the pump was installed with standard sch40 threaded adapters? specifically because your pump comes with 2" High-Temp unions...
The only reason i could think of is your plumbing is 1 1/2" (hard to tell from pics) and he did not have reducer bushings.