Sediment filter on backwash pipe work?

[BC78]

Does anyone know if a sediment filter is available for putting inline on the backwash/waste pipework.

The problem I have is we are on a island very close to the beach and will end up with a bunch of sand in the pool in the summer and our backwash system is pipped into our in ground drainage system for the gutters. What I don’t want to do is clog the draining system in the yard up with sand over the years of cleaning as that could be a very expensive problem so looking for some kind of inline filter system to filter that sand and all the other junk that will end up coming out that waste pipe.

 

[Texas Splash]

our backwash system is pipped into our in ground drainage system for the gutters.

Figured I'd ask the first question others may have ........ "Does it have to be?" Is there an ordnance for your area that states the waste line must go into a ground drainage system?

 

[BC78]

Figured I'd ask the first question others may have ........ "Does it have to be?" Is there an ordnance for your area that states the waste line must go into a ground drainage system?

No i should have mentioned that there is none but the houses are ontop on each other and currently i could waste to the empty lot next to me which the owner wouldn't mind but it's a bit more hassle as the line is hard piped to the gutter system in the ground. im thinking a filter sock would catch the worst of the problem material and maybe a robotic cleaner would also help. but would be nice to just have the backup of some kind of sediment filter on that main line.

 

[mknauss]

With sand, a pre filter (cyclonic) would be helpful in your situation.

 

[BC78]

With sand, a pre filter (cyclonic) would be helpful in your situation.

Thats a good idea. i just searched and found this and then thought a filter after that should stop almost 100% of that sand going down that drain.

Waterco MultiCyclone 50 Pre-Filter 2-Inch | 200375 200370

Pool Supply Unlimited has some of the best prices when shopping for Waterco MultiCyclone 50 Pre-Filter 2-Inch | 200375 200370

www.poolsupplyunlimited.com

 

[Bperry]

The force of backwash water will push sand through a sock pretty easy. Might be best to try one of those cyclones instead and have a robot clean it up as much as possible before it gets into the plumbing.

 

[JoyfulNoise]

You could install a separation tank that is normally used on DE filters to capture DE waste. It can be plumbed to the backwash line. But you will have to monitor it carefully as they can fill up fast. As others have posted, a cyclone pre-filter would be another option but I think the plumbing may be more challenging.

 

[mknauss]

The pre filter goes at the outlet of the pump. This keeps the sand from reaching the primary filter.

Thats a good idea. i just searched and found this and then thought a filter after that should stop almost 100% of that sand going down that drain.

 

[JamesW]

A separation tank would work, but you have to make sure that it is rated for the flow rate.

What is the pump size and flow rate?

What filter do you have?

How much sand is lost on backwash each cycle?

 

[1poolman1]

You could try this approach:

SlimeBag for 1/10 of the price, yes you can!

Long story short, I wanted cartridge filter clarity without a cartridge filter. I came up with an idea, tested it, and now I want to share it with others. I performed a forum search before making this post and learned of the "Slimebag". Low and behold, the "Slimebag" is equivalent to my idea...

www.troublefreepool.com

 

[JoyfulNoise]

I used a SlimeBag once before for a similar kind of application (capturing “crud” before return water to a pond) and I’d say I got it to work maybe half the time. Sometimes it would be great and stay on the whole time I used it and other times it would get blown off the end of the pipe it was attached to. I tried many different securing mechanisms to get it to stay put but could never get any of them to work either hassle free or without me babysitting it.

I’m not saying it isn’t possible for the OP and, given it’s low cost, it may work fine especially if it’s just for a short cycle backwash application. Just be warned that securing it to a straight pipe will not be easy. Some kind of locking mechanism will be required or else the backwash water will blow it right off the pipe.

 

[JamesW]

You can glue a T to the end of the pipe to make it hard for the bag to slip off.

You can use multiple bags if necessary to reduce the pressure and flow through any bag.

Use a T or a 4-way cross (or more than 1) to split the pipe into 2 or more lines and then put a T or a 4-way cross at the end of each line before securing the bag over the ends of the lines.

2" Schedule 40 PVC Cross 420-020

Buy 420-020 2" Schedule 40 PVC Cross at PVC Fittings Online and receive huge savings on all Schedule 80 CPVC, Schedule 80 PVC and Schedule 40 PVC fittings

www.pvcfittingsonline.com

 

[JamesW]

Bag Filter FAQs: When/How to Change, Size (#2 or #4), Type, and more

How do you change a bag filter? Should I be using a #2 or #4 size? What type of bag filter material? How long will my bag filter last? When should I change?

shop.prmfiltration.com

Should I be using a #2 or #4 size bag filter?

Virtually all industrial and commercial applications utilize trade size #2 or trade size #4 filters, which correspond with #2 and #4 size filter housings. The correct housing for an application is mostly determined by the flow rate.

A #4 size housing is appropriate for most applications up to 40 gpm, and a #2 size housing is appropriate for most applications up to 100 gpm. Multi-bag housings can generally handle flow rates greater than 100 gpm.

 

[JamesW]

https://www.clarionmunicipal.com/support-files/dewatering-bags-flyer.pdf

 

[JamesW]

Pipesock: Stormwater Filtration Sock - New Pig

Control and contain oil and sediment during dewatering with a PipeSock! Attach to hose or pipe to remove hydrocarbons and sediment from pumped water. At newpig.com.

www.newpig.com

https://www.lowes.com/pd/Hanes-Geo-Components-15-ft-x-10-ft-Polyester-Dewatering-Bag/5013975589

 

[JamesW]

Sediment Filter Bags, also known as Dirt Bags or Filter Pump Bags, are designed to control and filter silt and sediment laden water during dewatering activities.

Filter Bags are constructed of non-woven geotextile material that filters soil particles greater than 150 microns while allowing discharge water to pass through the bag.

Each bag has an adjustable spout to accommodate a discharge hose of up to 3 in.

• Made of 8 oz. non-woven filter fabric
• Large enough to be useful yet easy to handle
• Can accommodate up to a 3 in. discharge hose
• Filters out sediment and sand for safe disposal down the storm drain
• Will handle a very high water flow rate
• Can use the included tie string to seal bag

Mutual Industries 5 ft. x 6 ft. Black Non-Woven Dewatering Filter Bag 15925-500 - The Home Depot

Sediment Filter Bags, also known as Dirt Bags or Filter Pump Bags, are designed to control and filter silt and sediment had laden water during dewatering activities. Filter Bags are constructed of non-woven

www.homedepot.com

 

[JoyfulNoise]

Pipesock: Stormwater Filtration Sock - New Pig

Control and contain oil and sediment during dewatering with a PipeSock! Attach to hose or pipe to remove hydrocarbons and sediment from pumped water. At newpig.com.

www.newpig.com

View attachment 468370

https://www.lowes.com/pd/Hanes-Geo-Components-15-ft-x-10-ft-Polyester-Dewatering-Bag/5013975589

I can attest to using other Pig brand products for cleanup applications and spill containment and they make excellent materials. If that filter sock would work on your discharge pipe then Pig brand is definitely the “top shelf” in my opinion.

 

[JoyfulNoise]

i think it’s fair to say that you’re also kind of assuming that sediment from the filter’s backwash is NECESSARILY going to clog up your drain pipe. Honestly, if your talking about a 4” diameter drain pipe that is normally used to move roof gutter water away from the house, the pool’s backwash discharge is going to be a minor component of what goes through that pipe on an annual basis. Since you’re in coastal North Carolina (assuming that from your location info), you are going to get tons of rainwater every year that is going to flush out that line. Assuming the line was correctly placed with good grading and no low spots, all of the discharge form your filter backwash is going to get flushed away.

Have you actually measured how much sand is in your discharge water from a backwash?

I’m assuming you have a sand filter and so there isn’t any pool sand that should come out of the sand filter. The rest should be fairly minimal quantities of large debris and silt. Rain water flowing through the gutter system should easily move any of that.

Perhaps give it some time before you spend the money on a wild goose chase.

 

[JamesW]

The dewatering bag is only about $32.00, so maybe worth trying to see if there is anything worth catching.

Beach sand can layer on top of regular sand in a sand filter and it can sometimes backwash out, but in many cases, it will build up and affect the filtering ability of a sand filter.

It would be best to avoid getting any beach sand into a sand filter.

 

[JamesW]

Sand will quickly damage a multiport valve, so you should make every effort to avoid getting sand in the multiport and in the filter.

If you have to vacuum out sand, the best choice is to use a separate pump to vacuum directly to waste and not use your system at all.