New Larger Filter Running at Higher Pressure and Backwashing Sand Out

amccleskey

LifeTime Supporter
Aug 13, 2014
36
Sugar Hill, GA
We just replaced our Hayward S210T 200# sand filter with a larger Hayward S244T 300# sand filter. The old filter cracked and we were told it was under-sized for our pool and that a larger filter would clear the pool more quickly when it got cloudy, etc. We just got the new filter all setup and I'm curious if a couple of things are normal or not.

1. The new filter is running at 16 psi clean. Our old smaller filter ran at 10-12 psi clean, and I thought a larger filter would run at a similar pressure or even less? We did move the filter location. It used to sit up about 18" above water level and the new location is about 3" below water level. We have 1 1/2" pipe.

2. We just opened our pool and it was full of algae. I started a SLAM and started using the filter and I was having to backwash every two hours on average. The pressure was rising to 20+ psi really quickly. Our pressure never rose that fast on the old filter, even when clearing algae, and again since this is a larger filter I thought there would be more time between backwashing.

3. Last thing, I backwashed and rinsed the sand thoroughly before starting to filter. It has backwashed out at least 3+ cups of sand so far and there is a decent amount of sand that gets in the sightglass after each backwash. Is this normal for a new setup? The sand was AquaQuartz purchased at Leslie Pool Supply.

Thanks!
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
39,035
Tallahassee, FL
Did you use GREAT care to make sure NO sand got down the pipe? Are you SURE all of the laterals are on? Did you fill filter half way with water before adding the sand? THEN did you hand lay the sand under and around the laterals to make sure they don't get damaged?

The higher pressure could just be it being a new filter but that does seem high. Lets go through the above questions and see what you find.

You should not lose ANY sand with the back wash.

This is all adding up to taking the filter apart and starting all over with lots of picture so we can guide you.

Kim:kim:
 

amccleskey

LifeTime Supporter
Aug 13, 2014
36
Sugar Hill, GA
Hi Kim. Thanks for your reply. We did use great care not to get sand down the center pipe. The filter came with a little cardboard deflector that did a good job, however, we didn't check the laterals before filling it. We looked at them, but we didn't check to make sure they were connected well. We didn't fill it with water or hand lay the sand either. In adding the sand we were careful though. We didn't just dump it in there and the deflector piece helped to direct the sand toward the walls of the filter and not straight down on the laterals.

I've read differing information about backwashing and losing sand. Some threads say it's normal to lose some and some say you shouldn't, so I wasn't sure if it was okay or not.

We may end up having to take it apart to check. I will post some pictures of our setup also. If we have to take it apart, is a shop vac the easiest way to get the sand out so we can check the laterals?
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,892
Sebring, Florida
Your psi should be lower.....both because of elevation and size.....no doubt. So why is it higher?......increased resistance. The most common cause of increased resistance is because your sand is not being cleaned well.

What does your water look like right now?
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
21,742
San Dimas, CA (LA County)
I'm wondering if the sand is too fine. That would account for it really packing tight causing higher pressure, as well as slipping through the slots in the laterals and blowing into the pool.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
39,035
Tallahassee, FL
I do use a shop vac! MUCH easier on your hands! I put mine in my big wheel barrow and dump the sand into it as the vac fills up. MUCH easier for since that way you do not have to bend down so far to get it back up.

Kim:kim:
 

amccleskey

LifeTime Supporter
Aug 13, 2014
36
Sugar Hill, GA
Your psi should be lower.....both because of elevation and size.....no doubt. So why is it higher?......increased resistance. The most common cause of increased resistance is because your sand is not being cleaned well.

What does your water look like right now?
Sorry for the delay. Right now our water is milky green. I'm in the middle of a SLAM. We just opened the pool and it was full of algae like never before. We replaced our worn out tarp style pool cover with a mesh safety cover, and for some reason we seemed to get more algae this season. It's not unusual for us to open our pool and it's green, but this time it was green with floating clumps of algae on the surface and when I brush and vacuum there are strands of algae getting stuck in the bristles.

The 16psi is what I get immediately after a backwash and when I have the diverter on both main drain and skimmer, and then it changes to 12psi when I put it on skimmer only or main drain only.

- - - Updated - - -

I'm wondering if the sand is too fine. That would account for it really packing tight causing higher pressure, as well as slipping through the slots in the laterals and blowing into the pool.
This is my first experience with a new filter and sand change, so I don't have prior experience with what the consistency should look like, but that makes sense if it was too fine that it would cause those problems. It's definitely grittier than play sand. I looked up the brand we got online and it got good reviews from other pool owners.

This is a link to the sand we got AquaQuartz Pool Filter Sand - Fairmount Santrol

Here are a couple of pictures of our setup in case you see anything that doesn't look right. We had to add a 90 degree elbow to the plumbing to move the pump and filter behind the storage building.

IMG_1233.jpgIMG_1231.jpg
 

Flying Tivo

Well-known member
Jan 24, 2017
770
Monterrey, NL, Mexico
I also got some sand the first few backwashes and considerated them normal. If it continues after 10 backwashes then its better to look inside the filter.
I dont see any problems with your setup.

Felipe
 

amccleskey

LifeTime Supporter
Aug 13, 2014
36
Sugar Hill, GA
I'm still doing a SLAM and trying to get the pool clear. My chlorine held overnight, but the water is still really cloudy. I still backwash out sand each time and get a decent amount of sand in the sightglass. Today we finally had opportunity to take the filter apart and inspect the laterals. They were all attached well and none were broken. The sand level had dropped considerably from when we first put it in. Is that normal for it to compact down when the filter is full of water or should it pretty much stay at the same height? I'm wondering if we should inspect the spider gasket too? I'll need to find a thread on how to get to it.

Also, I'm wondering if @Richard320 is right and it's a sand issue. Here are pictures I took of the sand. Since I have no prior experience I don't know if this is what pool filter sand should look like of if it's too fine. There are definitely fine particles in there and there were also fine particles stuck in the slots of the laterals. Our sand is definitely finer than the HTH sand shown in this link My findings on how not all sand is created equal

IMG_1251.jpg
IMG_1252.jpg
IMG_1253.jpg
 

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