[drew51]

In the thread about using it as a seed starter are links to various studies, and it appears to be an excellent amendment. The conclusions of three studies said it was beneficial to use. I want to try it this year myself. Often with tomatoes in pots they dry very quickly, this should help the soil retain more moisture, yet keep soil aerated, so no need for perlite. Not to mention adding silicon trace mineral.

Silicon: deposited in cell walls , has been found to improve heat and drought tolerance and increase resistance to insects and fungal infections. Silicon, acting as a beneficial element can help to compensate for toxic levels of manganese, iron, phosphorus and aluminum as well as build a barrier against zinc deficiency . Plants with a regular supply of soluble silicon produce stronger, tougher cell walls creating a barrier from mouth of sucking insects . Tests have also found that silicon can be deposited by the plants at the site of a fungal infection to combat the infection of the attacking fungal disease . Much of the silicon found in the ground is not naturally usable as it is found in solids hard to break down easily however studies have shown that if you give your plant water , that it is just about impossible in most area's of the world to totally deprive your plant of silicon , as even distilled water contains a certain amount, it can however be helpful to add additional silicon to the system for extra benefit

The products with DE like UltraSorb or Optisorb, have some powder, this is where the plant can get silicon.
Use mask when handling!