Do soI think I’ve seen some 15mm filter foam sheet somewhere, I may give it a try if it’s not too expensive.
Have a look at <"Swiss Tropicals - Poret®aqua Media">.I feel like I have read somewhere that foam should be in whole blocks that fill the space they are in, otherwise most of the water will want to bypass the sponge (path of least resistance), and the sponge will therefore be less effective.
Looking at the stuff in the photo (not likely that I’ll see it IRL as the local ADA Rep has his own ideas as to what’s suitable to make His Order List) my guess it’s meant to simulate the ceramic mechanical filtration media ... of course most mechanical filter media will also become biological media over media (it’s just not as “optimized” re surface area/volume ratio, oxygenation, pore sizes, etc)Most of ADA’s stuff is well thought out, hence the original question. I guess it may help improve the flow over a solid block? ADA don’t actually intend this stuff to be used long term according to their info.