Aquaponics - Swirl filters for solids removal

Over the last few days, I've been reading a stack of stuff on radial flow and swirl filters.

Here's what I think I know so far.

As far as I can tell a radial flow filter moves the water in a very gentle manner, first down then up. The solids stay at the bottom. It often does this by having a container inside another container. One container acts like a bucket, and the other is mounted upside down from the lid. You add water and solid waste into the centre top, where it gently moves down to under the rim of the upside down container. The water then rises up to exit near the top outside rim, leaving the solids behind at the bottom. A tap is placed at the bottom so you can remove the solids.

I think I'm going with a swirl filter instead.

The swirl filter migrates solids towards the centre and the bottom, which should be the best position to remove them via a siphon. The path the solids take is a long one because the flow is circular due to the direction of flow on entry to the device. This allows more time for the solids to fall out of suspension (maybe).

So a swirl filter is a bucket with an inlet pipe mounted near the rim to introduce water and solid waste from the fish tank. The inlet tube is pointed in such a way as to make the water create a gentle whirlpool.

Normally, a tap is added to the bottom to remove the solids once collected.

As far as I can tell, a swirl filter changes the pressure of the water on the outside, making it higher than that of the centre due to it's rotational ... disposition.

This pressure (and depth) difference means that the top is no longer the top as far as the poop goes. The poop now thinks the top outside edge is the new top, and the bottom centre is the new bottom. So the poop moves to the new bottom which is right where I'l mount the bell siphon.

What all this means is that the poop is a little more committed to sinking than it's normal, only slightly sinking self.

It's also more likely to settle out near the centre of the bottom of the swirl filter.

Instead of using a tap mounted through the bottom of the swirl filter, I'll be adding an auto siphon in an attempt to automate the dumping of the solids into a worm farm.