Re: vermiculite/soil & pH problems

The Mermaid said:

"I'm using the vermiculite/soil & small grain gravel mixture 
	as substrate on my 40g tank.  I was finally able to get
	a high range PH test kit last night, and upon testing the
	water, the PH of the tank was WAY above what my tap water
	and my 10g tank are.  The 10g and tap water both read the
	same, at around 7.5 ... my 40g reads ~8.0 (purplish in
	color, as opposed to orangish)."

Come to think of it, I have had the same problems you are referring to with regards to pH. 
I am using a vermiculite/loam mixture in my 20g long tank. I have never been able to get my  
pH below about 8. I use a 1/5 dilution of tap water with RO water in my tank which 
brings the GH down to around 2 and the KH to about 5-6. I am getting amazing growth of 
all the plants, though, and have very little trouble with algae. I finally convinced myself 
that I'm just not getting good dissolution of CO2 (but its good enough so that I must trim 
the plants once every two weeks). Anyway, I'll be interested to hear what comes of this. 
Robb D. VanPutte
Dept. of Biology
Texas A&M University