Sand Filter Issues...

[AJC9725]

I think my filter may be having some issues. I just purchased a new 1 hp Hayward Max-Flo pump, and matching 21" sand filter this season. I did not install it, but a very highly recommended family business did. Ever since the first backwash, I would notice sand coming out in my driveway. I read up on this, and saw that this was not out of the ordinary for a new filter, but 3 months later, I am still seeing some sand come out when backwashing.

The bigger issue is that I feel it isn't trapping dirt very effectively. I have been away from home from much of the past 3 weeks, so when I vacuumed yesterday, the pool had a fair amount of dirt. I got most of it, but the stirring of the water made the deep end pretty cloudy with dirt. Fast forward to today, and the deep end is still pretty cloudy, and there is new lines of dirt in the shallow end as well. Also, I have gone stretches of weeks without seeing a single psi increase on the filter.

I made sure to rinse thoroughly after each backwash to prevent channeling, but something doesn't seem right. Does anyone have any suggestions to troubleshoot the issue? Thanks for the help.

 

[lefty51]

hello and welcome, I'm nor exactly what kind of sand filter you have, but off the top of my head I think that the person who installed it might have forgotten or broke one of the laterals inside the tank. Generally sand filters have a main standpipe with laterals that screw in at the base of the pipe. These laterals have small slits in them that allow water to pass through and stops sand and debris from getting past. If one of them is missing(or more likely broken) it will let everything pass through. That would explain the sand in the backwash water and would also explain the dirt(and probably) sand you are seeing in the pool.

I might add, it will do a lousy job of filtering and lead to the bad stuff just re entering the pool. Also I would think there would not be a lot of pressure on the gauge, let alone an increase. Hope that helps. Be sure to let us know what you find out or if you have anymore questions

 

[AJC9725]

Is there any way to check if one is damaged besides removing all the sand?

 

[lefty51]

Is there any way to check if one is damaged besides removing all the sand?

If you can remove the top and bury your hand down far enough to feel the laterals you MIGHT be able to feel if there is a hole in the stand pipe where a lateral SHOULD be screwed in. And you could feel along each lateral to see if you can feel if one is broken or if one has a large gap or hole in it. If you could look at a parts diagram of the filter you could get an idea what they look like so you would have an idea what you should be feeling. Other than that it's take out the sand and visually inspect, .

Someone will read this and possibly have a better idea, these folks are Pretty smart around here

 

[f3justusc]

If there is a warranty from the company that installed the filter, I would ask them to come back because something is not right. If you have as much sand in the pool as you say, you may not have much left in the filter and it will be easy enough for you to check. However, if this is the result of an incorrect install, you might want to let the installer sort it out.

 

[AJC9725]

I have not noticed any sand in the pool...just in the driveway after backwashing...

 

[f3justusc]

Ah, that definitely sounds like an issue with the filter internal parts. I searched the forum and most are saying laterals or spider gasket. You can check the gasket by removing the top of the filter. You do not have to go into the filter. I have sand in my backwash every time

 

[lefty51]

Ah, that definitely sounds like an issue with the filter internal parts. I searched the forum and most are saying laterals or spider gasket. You can check the gasket by removing the top of the filter. You do not have to go into the filter. I have sand in my backwash every time

Good catch f3, I was just about to post that depending on the filter, there have been posts about the spider gasket in the multiport valve. I don't know if that is something that could have been left out or improperly installed, but if no sand in the pool I think we can rule out broken lateral. Like f3 posted earlier, if there is a warranty on the install I would contact them to see if they would give it a look see.

 

[AJC9725]

Just called the guy that installed it...he said it's fairly normal to see sand coming out during backwash for the first season or so, because he generally would rather put in 'too much, rather than too little'...also, he said since sand filters are the least fine of all the filtering methods, it's not uncommon to have to vacuum multiple days in a row if the pool is pretty dirty. The sand isn't fine enough to trap everything, and lets a certain amount through....

Am I buying into this response, or should I investigate further?

 

[99taws6]

I call BS on his it's normal to have sand not trap everything excuse.

 

[lefty51]

I would think that if some sand was allowed to fall into the stand pipe you would certainly have sand in the backwash and/or pool. But after three months it surely would be gone by now. I don't quite understand the "too much, rather than not enough" comment. There is a certain amount to add depending on the filter, too much can lead to problems. That being said if everything is right sand should NOT be coming out in the backwash after this amount of time.

As far as having to vacuum multiple days in a row, unless there is a lot of debris entering your pool or you have an algae outbreak, you shouldn't have to vacuum that often. I only vacuum every two weeks or once a week at most. And that's with regular brushing and bather load. If we have a storm, there are leaves and debris sometimes, but that's it. I question his willingness to double check his work. ( in my opinion )

 

[f3justusc]

Investigation required. Unless they filled it to the top, that explanation does not make sense. If you can get them to come out do it. If it is going to be a hassle, it is easy to check the gasket and the laterals too. I found that not always turning the handle clockwise caused my spider gasket to unseat. It took maybe 30 minutes to remove the screws, lube the gasket, and put it back together.

- - - Updated - - -

And.... I have an Intex sand filter with a Hayward pump. The filter catches enough for me to have a sparkling pool.

 

[AJC9725]

OK, I will check out the gasket. I definitely do not turn the multipart valve clockwise every time. I will start doing that.

 

[f3justusc]

Always turn it clockwise. I am sure you know this but to reiterate, always turn the pump off before changing the filter valve position.

 

[f3justusc]

I really hope the OP returns with an update...

 

[lefty51]

I really hope the OP returns with an update...

me too, not only to know what the problem was, but to hear another "odd" statement from the installer

 

[f3justusc]

me too, not only to know what the problem was, but to hear another "odd" statement from the installer

That too. Made me laugh thinking about it.

 

[duraleigh]

Sand filters have a pretty definitive "fill line" and that's what should be used. If their installer over-filled with sand, the turmoil in the filter could easily blow sand out the backwash valve.

Over filling does no good.

OP should look in filter manual and see how much "freeboard" his filter should have and then open filter and insure sand is at that level.

 

[Hayward Pool]

I am going to put forward my two cents. All sand filter need a freeboard area of a certain height above the sand bed. This prevents the heavier sand but not the debris from coming out of the filter during backwashing. If someone adds too much sand you could get sand coming out during backwashing until the sand bed is lowered. The fact that no sand is coming out of the filter during normal operation tells me the laterals are ok. If the laterals were compromise you would have sand coming back to the pool. Also make sure to let the sand filter build some pressure. I dirty sand filter becomes a better filter. The debris helps filter smaller particles.

 

[raynesci]

I think most filters have a recommended amount of sand based on weight. This is either on a label on the filter itself or in the manual.