Planted Tank Guru
Join Date: May 2011
Location: Chattanooga, TN
Its a standard fired clay substrate. It is much the same as terra cotta. Plants cant send there roots through the clay. Just the first small pores they attach to. After that the porous inner structure is too small to allow roots to reach, or for that matter water to pull nutrients out off.
If i were to make a clay pot, i could add in tons and tons of ammonia and phosphates and say that my pot would help grow any plant better than the competitors pot, but once the plant roots extract everything from the surface they can reach, the pot is still just a pot, but i can say its got 50000000 ppm of ammonia locked inside
This is prett much how flourite and eco complete work. The good news is they are able because of this to exchange cations allowing them to hold nutrients in the water, making them available for plantsr later on. So if u dont fertilize, when u feed and it gets broken down, and change water, the subsrate acts like a sponge and holds onto as much as it can thus maintaining consistent growth, this works out well in a low tech tank, but in a well fertilized tank, you'll never see this happen as plants can easily absorb nutrients from the water column