View Full Version : Converting from cartridge to sand???

08-14-2006, 04:29 PM
I currently have a Fox Wall-Pak cartridge filter and am considering switching to a sand filter because these cartiridges have been a pain for me and have led to some cloudy conditions in the pool this season.

Essentially, in the filter housing, I have 2 cartridges, 1 for the skimmer intake and one for the main return intake at the bottom of the deep-end. The pump is about 15' away on the side of the house. It's a 1hp pump. There's also a chlorine feeder next to the pump in the return line, but this pool was using biguanide, so the feeder is just in the loop.

Where would the sand filter go, before the pump or after?

Is this too big a job for joe do-it-yourself?

What about the Wall-pak? Keep the housing to use the skimmer but ditch the cartridges?

Any comments suggestions would be great.

15000gal inground rectangle pool...

08-14-2006, 06:43 PM
Mariner, what follows is a mix of personal preferences and experience. I'm not very fond of cart filters (though they are the best type for some people - especially those who live in areas with water use restrictions).
The sand filter would have to be plumbed in after the pump, sand filters (and DE) are 'force fed' the water. (While I've brought up DE filters, have you considered one? - they do the best job of filtering small particles, but require more maintenance on your part) A sand or DE filter will allow you to have a 'multiport', which opens up a few great options for you (you can 'waste' the water if it's too high, or 'vacuum to waste' if there's a huge amount of debris in the pool, 'recirculate' the water if you have filter trouble, clean the filter by 'backwashing' - rather than having to hose off the carts (though DE filters need to be hosed off, at least yearly).
To be quite honest, I have no earthly idea what a "wall-pak' system is.
As for doing it yourself, if you have the room at the filter system, understand where you want the water to come in and go out, and the ability to read the directions on the back of the can of PVC glue - you can easily do it yourself (especially with all the help you'd get here if you had questions)
As a last note, make sure you get a filter that's big enough to handle your needs. :)

08-14-2006, 11:13 PM
You bring up many valid points.

I'm very limited with my current setup as there is no backwash. Vacuum is done with a Ray-vac (pressure return).

Picture a box mounted next to the pool with 2 canister drums. One is the skimmer, pulling water from the surface, and the 2nd drum is from the main return at the bottom of the pool. This drum has a sealed lid, thus the pump draws evenly from both sources through the cartridges.

I have to rinse the cartridges almost every day to preserve proper flow to keep the water clear. I'm currently using Softswim, which is part of the problem, but my family seems to enjoy it and are hesitent to switch to chlorine. My wallet says please do...

I'll try to post some pics in the next couple of days so I can get some better feedback.

I grew up with a sand filter, so it's good for me.

DE seems like more work, but maybe not as much day to day as my current combo.

I know 2 people using biguanide products with sand filters and they're very happy.

08-15-2006, 07:28 AM
OK, I think I got it. A cart has two openings, in and out. A sand filter has three, and they all go through the 6-way valve that's part of it: In, Out, and Waste.

The skimmers and drain flow to the pump, through the pump's basket, then out the pump into the filter's intake. The filter's output goes to the pool's return. The waste can either have a hose that gets rolled up, or can be permanently hooked to a drain. That's really all there is.

For every person who likes Bacquacil you'll find 10 to 20 who hate it. It's a large reason for your problems. Backwashing sand is a snap, especially if you have it plumbed into a drain. But switching to chlorine will save you a ton of money and be less work. Very few people are actually bothered by chlorine--that's a fairy tale. What bothers them is a poorly maintained chlorine pool--and if you follow the rules here you'll never have that problem. Nobody is EVERY irritated in my pool--because I follow the simple rules. The bac will goop up your sand filter too, and you'll have to replace the sand. I'd convert to chlorine, complete the conversion, then put in the sand filter.

We have been adding DE to our sand filters, a number of us, with EXCELLENT results. You add 1/3 to 1 cup every time you backwash. I started over a year ago, and am still using the first 5 pound bag in the 10 pound box--which cost me all of 8 bucks. Another 5 bucks spent on a set of Skimmer sock clones and my filtering gets even better faster.

DE IS better at filtering than sand, it IS slightly more work, but with DE in the sand and the skimmer socks, I have NO complaints.

If you are Handy Andy, putting in the sand filter should be easy. If you are all thumbs and the only nail you can hit is the one on your thumb, then you'd better get help. It's easier if you use TigerFlex flexible PVC than the hard stuff, but the hard PVC is pretty easy to work with too. With TigerFlex, you use glue-on fittings just like the hard PVC...don't be conned into using internal fittings and hose clamps--TigerFlex isn't made for them and always leaks. Use ONLY fittings rated for Schedule 40 or higher (Schedule 80 is OK but expensive). Spring for LOTS of quick releases--they make life SO much easier.

08-16-2006, 07:54 AM
Just do it!
I was in the same situation last year. I had a cartridge filter under the skimmer, in the same housing. I constantly had to clean it to keep the flow up. I would need to change it weekly if not sooner. By the end of the season both cartridges were trashed and I had to buy 2 new ones each year. I was spendign 100 dollars a season on filter, constant maintenance and always fighting algea. I opted to go for a sand filter. I got a good deal off an authorized Hayward retailer on Ebay. I purchased a 100 lbs sand filter and a Power Flo pump. I have never had more enjoyment as a pool owner as this year. The water is always crystal clear. I backwashed twice this season, so far. Ever since my upgrade the pool has been more enjoyment and ALOT less maintenance. I strongly dislike cartridge filter due to my experience. I would recommend a properly sized sand filter and pump. I have not added DE to the sand but have been considering it. The ability to backwash and vac to waste is priceless. I am sure if you follow the advice given here at poolforum you will become a happy pool owner and more of a pool user.


08-16-2006, 10:38 AM
i don't think it was mentioned, but if going to a sand filter...let's not forget that as an option with much better filtering capability then sand. i switched from sand to zeobrite about a month ago and noticeable improvement in filtering.

08-16-2006, 10:10 PM
I was in the same situation last year. I had a cartridge filter ... I constantly had to clean it to keep the flow up. I would need to change it weekly if not sooner. By the end of the season both cartridges were trashed and I had to buy 2 new ones each year. I was spendign 100 dollars a season on filter, constant maintenance and always fighting algea.

Pretty much my story, too. I was also cleaning daily. I was going through about three cartridges a season. I also decided to get a sand filter.

Except ... I converted to chlorine, first. I still haven't bought that sand filter. I'm still on my first cartridge filter this season. It NEVER goes above 10 psi. I do clean it once a week - I'm getting a lot of dirt blown in from a three acre lot behind that is being developed. My pool is always crystal clear.

Carl is right, bacquacil too easily clogs up the filter, making it ineffective.