Summary of Key Differences: Walstad Method vs Father Fish Modification of the Walstad Method

I'm a newbie to planted tanks, and have spent the last 2 month researching how to set up a planted aquarium.

Two schools of thought have attracted me: the Walstad (W) method, and a later variant by the Father Fish (FF) youtube channel. The following is my personal understanding as a newbie.

FF has a video where he acknowledges Diana Walstad's book was a major influence on him, and he said he started off using the Walstad method. However, he subsequently modified it to the extent that I believe it presents conceptual differences.

A first key difference is that, on top of the soil, (W) uses 1" gravel versus (FF) uses 2" fine sand. The rationale is that, in (W), the thinner 1" layer of 2-3mm gravel does not effectively isolate the soil from the water - because of the greater porosity of tiny gaps between the 2-3mm gravel. Whereas, in (FF), the thicker 2" layer of fine sand has a comparatively greater ability to isolate the soil from the water.

(Note: in some countries, 2-3mm gravel is called "sand" which can confuse the discussion among different people. Hence, the sand used in the FF method would be the significantly finer sand akin to the size of minuscule granules, for example, found in children's play sand.)

Consequences of using 2x thicker substrate and finer sand:

(W) fish cannot be added for several weeks/months, whereas (FF) fish can, and should, be added immediately from Day-2 since the presence of fish is seen as a key component that aids in establishing a biological ecosystem. This ability to add fish from Day-2 is because the 2" sand layer, to a greater extent, hinders the soil-nutrients from leaching into the water, whereas (W) the use of 1" gravel of size 2-3mm means that the soil more readily leaches its nutrients into the water that could be detrimental to fish if these are added too soon.

The difference is in (W) 2-3mm gravel vs (FF) fine sand.

The other difference is (W) being a 1" layer, versus (FF) being a 2" layer.

(W) Because the water effectively comes into contact with the soil through the porosity of 1" layer of 2-3mm gravel, it is useful, before setting up the (W) tank, to pre-treat the soil (called "mineralisation") so that the soil does not have such an initial negative effect on the water. Whereas (FF), because the soil is sealed off to a greater extent due to the fine 2" sand layer, the soil layer can be fortified with a host of extra nutrients before it is laid down in the tank. In FF, the prior mineralisation process is not needed before the tank is set up.

Other than these differences, it appears to me that (W) and (FF) are mostly consistent on other issues, such as the prime importance of plants in establishing an ecosystem in the tank.

I'd be interested to hear comments on what I understand to be key differences between the (W) and (FF) approaches to substrates.

Disclaimer: the above is from my newbie research from the last 2 months, and neither (W) nor (FF) were aware that I would write this.