Tomatoville® Gardening Forums - View Single Post - Diatomaceous Earth as a seed starting medium

RayR · October 4, 2012

I think you are going to have a problem with pool filter DE aside from the fact that it has high levels of fine crystalline silica particles and is dangerous to work with.
The fine powder is like food grade DE and is not ideal at all for horticulture. There will be much cohesion between the particles in water and it will choke off oxygen from the roots. It's like trying to grow in very fine clay.

You really need a coarser aggregate. You can't even find Moltan Ultrasorb or Optisorb at the local auto parts stores?

October 4, 2012	#153
RayR Tomatovillian™ Join Date: Jun 2010 Location: Cheektowaga, NY Posts: 2,466	I think you are going to have a problem with pool filter DE aside from the fact that it has high levels of fine crystalline silica particles and is dangerous to work with. The fine powder is like food grade DE and is not ideal at all for horticulture. There will be much cohesion between the particles in water and it will choke off oxygen from the roots. It's like trying to grow in very fine clay. You really need a coarser aggregate. You can't even find Moltan Ultrasorb or Optisorb at the local auto parts stores?