Swimming pool filter

(Teresa Shipley) #1

We would like to change the sand in our filter to glass. We contacted a pool company but because our filter sits at the back of a small pool house with limited head room they recommended that we do it ourselves as it would be very expensive due to the time it would take.
My question is do we buy glass medium to put in the existing filter or do we have to have a complete new filter?
Also what should we expect to roughly spend?
We don’t think the sand has been replaced ever and is probably 12 years old.


(John Withall) #2

Teresa, what filter have you got? Name, top mounted valve or side mounted? You can fit the glass media into your existing filter, the reason for asking is to see what you currently have and then I maybe able to advise clearer.
If you are replacing with glass media, please only use AFM from Dryden Aqua as many of the knock offs are worse than sand.


(Teresa Shipley) #3

Thank you. I hope this photo is some help.



(Teresa Shipley) #4

I think it says galactic.


(John Withall) #5

Yep, and side mounted valve so no need to consider changing the filter. Plenty of room for changing the sand to glass as well so your pool company are crap, better off without them.

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(Teresa Shipley) #6

So does the sand go in the top. The room above top is about 7 inches. Do you think we can change the sand in situ? Also do we hire a vacuum to suck the sand out and where from please?
Thanks for your time.


(Dave Sheriton) #7

Teresa, after the first filter I tried to change without a vacuum I realised it was a false economy and was worth every penny. I always hire mine from Loc+ and the one I had last Friday ended up at 49€ for the whole day. (I was changing a 340kg filter and a 70kg filter). You might get away with half a day hire which will be less. The only concern is whether there is enough manouverability above it to a) get the pipe in and b) be able to see inside the filter as to how you are doing.


(Teresa Shipley) #8

Thank you. My husband thinks we may have to get the filter out of the pump house. It’s a lovely discreet little pump house if you don’t mind bending double.:rofl:
I’m lining up a couple of you tube videos before we attempt to change the sand.
Did you replace sand with sand or glass?


(Dave Sheriton) #9

All the filters I look after are sand, so don’t have any useful info about glass filtration. It’s not a difficult job, take your time and I’m sure you’ll be fine.


(John Withall) #10

Hi Teresa,
Yes the sand goes in and comes out the top. You’ll have enough room at 7", shame your photo didn’t show what was above and obstructing. A domestic wet vac would be fine for that size of filter, the sort from a Brico shed. Probably cost less than hiring, you may even know someone who has one you could borrow.

The cover removed, the next part is the diffuser that will be in your way, some unscrew, some swivel out of the way. With that moved you’ll have access to the sand, with space tight use a mirror to look inside the tank. You can wash down the sand into the bottom with a hose to make it easier to remove.

A word about the sand, it has been filtering all sorts from the pool for years, it can contain all sorts of nasties so wear gloves and I also wear a P3 grade mask, it’s a potential biohazard.

In the bottom of the filter there are the laterals, an arrangement of 6-8 tubes with fine slots to allow the water to pass, be careful as they can get broken with heavy handed cleaning. They can also get broken by attempting to move a full filter. I have the contents of 4 filters moved by “helpful” builders when they were full, I just keep them for the odd spare part.

You tube also a warning of people not knowing what they are doing! Whether you decide to relocate your filter to a better place once empty is up to you. But when you commence re-filling with sand/glass etc make sure to put a bag or bung over the central pipe that takes the diffuser to prevent media ending up in the pool. Half fill the filter with water, this slows down the media hitting the laterals and risk breaking them but also dampens down any dust from the media (dust mask) sand contains a lot of free silica dust and glass is well glass neither of which you want to breathe in. Always backwash new media before any other operation, worth putting the valve into backwash before you start so you remember. Two good 5 minute backwashes with a rinse in between should suffice but check with a piece of written text held under the sight glass on the valve to be sure the water is running clear before putting the valve on to filter.

AFM glass from Dryden aqua, It is self sterilising so bacteria cannot colonise it unlike sand. It never needs changing, It won’t clump (mud ball) like sand. It filters much finer than the best sand and washes cleaner, what we filter out of the pool we must be able to get out of the filter to. The more we remove from the pool water the less there is for chlorine to do so we reduce the nasty chloramines (the smelly pool water, blamed on chlorine) but actually the nasty by product. so you will use less chlorine. You will have to backwash a little more frequently with AFM to start with because it will be removing more fine dirt and bacteria/algae spores etc.



(Teresa Shipley) #11

Thank you.
There is actually a solid concrete/stone ceiling above the filter. It’s certainly wasn’t built for easy maintenance.
In the event we do break any laterals are they easy to replace please?


(John Withall) #12

The laterals are quite tough plastic but after many years in chlorinated water they can become brittle. Replacements are available.
One important point I missed off, remember to open the air bleed screw in the top of the filter when allowing the water back in following a media change or any other scenario where the water has been drained from the filter. Other wise the air will get pressurised and can cause a small explosion meaning the ruin of the filter.

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(Barry Wood) #13

Hi John where do you get your AFM glass from?


(Mark Lewis) #14

Hi, new to the site but this thread caught my attention. We have just purchased a house In Dordogne with the exact same pool filter and operating system. However apart from the pump operating manual we have no other operating instructions. Any idea where I can obtain these from? Many thanks Mark.