Small pool, big filter - media choice.

[AUSpool]

I’m really asking here for thoughts on media size per quantity. I’m upsizing the sand / media filter to match the VS pump to maintain 2” plumbing throughout. The manufacturer recommends 7 bags of fine media with 4 bags of course media. But as this will be a small pool with a big filter, running mostly on lower speeds, maybe I would be better with 8 bags of fine with 3 bags of course.

So here’s the detail. We are about to build a new pool. A small one. 5 x 2.9m (16’ x 9.5’) @ 20kL (5.3kUSgal). The manufacturers confirmed what I have always thought in that a mix course and fine media will eventually mix. So once mixed I’m thinking an extra bag of fine would help the filtration capacity without constricting the flow.

And while I’m here I would like to introduce a new brand Insnrg, pronounced in-sin-er-gy. These are produced by the people that bought us in AU the Astral range. I love the look of the pump and SWG but I’m afraid it’s beyond my budget.

 

[JoyfulNoise]

I’ll leave the filter questions up to someone else but I will comment the Insnrg stuff looks fancy but isn’t really anything better than what’s already out on the market. Their highest output SWG produces 2.1lbs/day (for those of us still in English standard units) which is about What you find here in the US with a Pentair IC60 or a CircuPool RJ-45. I don’t think they’re doing anything special other than making the packaging look slick. So if you can find Astral brand SWG with similar output and a lower price (or sone other Aussie brand), you’re not missing anything important.

Good luck on the pool build.

 

[AUSpool]

Thanks Matt,

I’ve answered my filter media question - stay with the manufacturers ratios which kind of makes sense, maybe. Enough course to cover the laterals and then fill it up with fine. It is assumed that there will be a lot of mixing over time. Information on equipment here is a bit backwards. The major brands don’t provide tech support, they refer you to the retailers, the pool shops, and we all know how that works.

I do like the look of the insyng pump but I couldn’t justify the extra cost. Their SWG cell is a departure from the norm. It has a vertical orientation where everything else I’ve seen is horizontal. They believe it works better with low flow applications. It has two probe ports in the top lid. I thought the cell would influence the probe readings but they said that from trials, once the flow is established, there is no difference between the cell pH and pool pH.

I have height restrictions so a vertical SWG cell wont fit. Even with floor level adjustments I will still need a side entry filter to fit a SWG cell in. That’s sound advice, similar output at a lower cost, and that’s exactly what we’re doing. Our pool builder supplies Astral as standard so thats what we’ll be using. One decision ticked off, on to the next.

 

[JoyfulNoise]

Mixed aggregate beds in the US are typically only found in very large, commercial sand filters. Using large aggregate at the laterals typically enhances flow rate but doesn’t really change the filtration much. As you say, it will all eventually get mixed up. In the US, most sand filters on residential pools just use #20 pool sand for filling.

 

[AUSpool]

Good to know, a bit of info I might be able to pass on. I just realised my question is probably moot as the builder will be doing the install but its still nice to know. It was mentioned that as it mixes the little grains fill the voids formed by the big grains. And then I can add a little DE to fill gaps between the little grains.