Intex natural swimming pool build w/ pictures

I recently assembled an Intex above-ground pool with a DIY Biofilm Substrate Filter made out of two IBC totes.
Construction was based on the book How to Build a Natural Swimming Pool by Wolfram Kircher and Andreas Thon
The swimming pool is roughly 2.80 x 5.5 meters. I used two IBC totes instead of the recommended three (based on the area of the pool)
because I ran out of blocks on which to set the IBC totes. I also only filled them up halfway because the substrate I had access to was unwashed
and getting all of the dust out was extremely tedious (I ultimately gave up and let everything wash into the pool, used alum as a flocculant and vacuumed it out).
I bought a pump that's much more powerful than necessary because it was the only one in stock, and I wanted to get the project finished THIS summer.
I assume that the increased percolation rate will at least partially make up for the smaller (and frankly, shoddily constructed) filter.

We are roughly two weeks post-build and the water is quite clean. Haven't used any chemicals other than the alum. I vacuum it regularly with a small pool vac, and remove
dead bugs and leaves with a net. Here are some pictures:


Ground preparation for the pool




Supports for the IBC totes. There was a larger-than-expected height difference...




Water distribution pipework at the bottom of the IBC tote, before filling with substrate. In retrospect, one horizontal pipe would have been enough for even distribution...




A gravel and stone pathway to prevent the creation and propagation of mud into the pool




The water is crystal clear. Hopefully it stays this way...

Good stuff! No chlorine. Did it keep up? How much electricity does it use?

Hi! Just coming across this after extensive googling - you seem to be the only person on the internet who has attempted this! Would love to know how it has held up and whether you have any more recent pictures. Also, I assume the book gives pretty clear instructions on the filter construction?

Maurine, welcome to the forum.

You might find this book helpful:

https://permies.com/wiki/65009/Building-Natural-Ponds-Robert-Pavlis

Are you using the Intex pool or designing a natural swimming pool?

This thread might help if the pool is a natural pool:

https://permies.com/t/68633/designing-pond

I am looking forward to hearing from Daniel as to how this worked since 2019.

Hi Maurine,

The book provides a decent amount of detail but far from enough. There is a lot of trial and error involved (a.k.a. time and money spent). I've had varying levels of success since I started and I'm on version 3.0 already.
The truth is, I'm far from satisfied with the results thus far, and I'm only keeping at it because I'm stubborn, and because I have an EXTREMELY supportive wife who doesn't make my life difficult beyond the occasional eye-roll.
That being said, my pool is not a disaster. Most of the time it is either swimmable or can be made swimmable, but the amount of effort required is more than I imagined (and frankly have time for), and the water quality is not where I'd like it to be. There are plenty of companies out there that at least claim to be able to provide crystal clear water without nasty chemicals and I'm not willing to stop till I get there. My goal is to figure out an affordable way for a DIYer to create a healthy swimming option and share it with the community.

I'll just quickly add this - "natural" is a very subjective term that I no longer like using. My goal is to have a pool that has high water quality without being a chemical soup.
For example, this year I added a UV filter. The book is opposed to this because it's not "natural". My view is different - the filter isn't harmful to swimmers because the UV rays are confined to the tube and there is no residual effect on the water. Anything that improves water quality without being dangerous or unpleasant to swimmers is okay in my view. I also want to experiment with bubbling ozone into the pool in small quantities. Ozone isn't healthy to breathe in, but it decays very quickly (15 minute half-life) and the only by-product is oxygen. It's supposed to have an extremely positive effect on water quality and if I run it a bit at night when no one is swimming it shouldn't be an issue.
The bio filter is still the central part of the system in terms of removing nutrients from the water to prevent algae, but I need to be able to handle edge cases with minimum down-time and maintenance effort.

I will write a post later today updating on my various attempts thus far, hopefully with pictures.

Beautiful!  And easy fix is baking soda for the water :)

Hi Daniel, any updates to your Intex pool experiment? Glad I found you here, because I also thought the idea would be obvious and was wondering why there is not so much out there yet. I'm even thinking if it would work to put the regeneration zone inside the pool itself, e.g. fill large plastic buckets with gravel and stack them on top of each other kind of like stairs or put a whole IPC container inside. I don't need such a big swimming zone, so I thought that would kind of be the easiest way.