Join Date: Feb 2009
Location: Portland, Oregon USA
If your asking what to cap it with, just use sand. You can buy a 20 lb bag of it at fred meyers for around $5. If your asking if you need to add anything else for nutrients i wouldnt, just stick to the recipe for MTS and cap with sand.
On a side note, you can get really good red clay in powder form from Georgies here in portland OR., they have a website and will ship. I think i bought it at around $1 a pound. Worked great.