If a mix is good at wicking water all the way up then it would have a very high perched water height too without the wicking. 511 is designed to keep the perched water very low and provide lots of air spaces. So a well made 511 will never be able to wick water the way you intend to. In other words a mix able to wick water high up will not have good aeration since those air spaces will be saturated with water.

I have no experience with hydro or similar techniques but to me ebb-flow hydro technique sounds a good balance of providing water/nutrients and air to the roots.

Is there a way to increase air space in a retentive mix? Compared to peat, a medium composed of uniformly larger particles that were still small enough to hold perched water, would have more air space and total porosity, right? Like a version of gritty mix where all of the particles are between 1/8" and 1/16". Or is it just not worth the hassle?

Does a retentive mix form a perched water table when wick watered, the same way it does when top watered?

The mix I asked about in the first post, 2-4-1 bark-peat-turface, looks to have that issue where there is enough peat to fill in around all the large particles, making it actually worse than just peat. Right?

Let us get some definitions right. Perched water height is a property of a particular soil mix (or any collection of particles). It says that for a given soil mix when thoroughly water will have its bottom saturated with water to a particular height. Above that height it will not be saturated no matter how much you water. Take a sponge and dip it in water and wait for say 20 min. You will see the bottom say 5 inches will be saturated - it wicks up water to a certain height. If you take a different sponge, say it is coarser, the saturated height will be lower say 2 inches. The top of the sponge will be dry no matter how long you wait. In other words the water will not wick up any further.

As far as perched water height is concerned it does not matter whether one waters from the bottom or from the top. The only difference will be that, in our example, the top of the sponge will be moist too but not saturated. Saturation means that all air spaces in the sponge is also filled with water.

Every soil mix has its own max height of perched water. A pure peat based medium has a very high perched water. If you now add some bigger particles to peat perched water height will not change initially. That is because water can still easily follow the peat particles upwards because they all touch each other. That is there is way for the water to wick up. As you start adding more of the bigger particles, say perlite, this path through peat gradually is broken up. But still you will have perlite surrounded by mostly peat. It will still wick up water as before and aeration will still suffer. When the bulk of the mix is perlite, say around 80%, then the situation reverses. Now the perlite will create air spaces and some of those spaces may be filled with peat. But the peat is no longer connected to other spaces filled with peat. There is no way water can wick upwards since there is no continuous path through peat. In this case perched water will be way lower.

Now let us see it from the other side. Start with a mix of pure coarse perlite. It will have very little ability to wick up water since the air spaces are big enough that water cannot travel upwards. Like a very coarse sponge. Instead if you use very fine perlite it will act just like peat. The air gaps between particles are small enough that water will wick up due to surface tension of water. Just like a fine sponge.

Remember the ability to wick water is dependent on the size of the air spaces between and within particles. Fine sand will wick water considerably since the air space between fine sand is small although sand itself cannot absorb any water.

Having said all that it may be possible with carefully screened turface. Water can wick up through internal pores of turface but they need to be small enough to be in good contact with each other. But they should be big enough so that there are large enough air space where water cannot accumulate.

Boy that turned out be long.