Trial of clay as a substrate additive

Sparked by the old thread I read about clay as a substrate, I pursued it further since
the Dupla K was costing me way too much.

I made some calls around Houston and after about 8 calls, I found some iron rich red clay.
Red Art Clay is what it is.  I purchased a 25lb. bag for $6.00.  

Thus far, I have rolled some pieces of the clay into small balls and I am letting
them dry out a bit before I try to insert them into the gravel.  I am just afraid of how much they
will cloud the water.  Then again, when I stir up the gravel which contains Dupla-K at the
moment, it gets a bit cloudy. <shrug>

Anyone tried clay yet?  I'd like come more comments about it without striking up another clay analysis thread <g>.

Tyson Lee
tyson at phoenix_net