Dave, thank you for this helpful info. Thanks to everyone who replied. I
also currently do 15-20gal changes in my 55g tank approx weekly. Hoping to
do more when I get the RO/DI set up. I have no form of added chlorine, as I
have well-water.

bob



"Dave Millman"
My plant tank flourishes on pure RO water. I reconstitute as follows, per
weekly
20 gallon (30%) water change:

2 teaspoons Kent RO Right
1 teaspoon sodium bicarbonate (actually baking soda, restores KH)
2ml Prime (neither RO filter nor charcoal prefilter removes chloramines)

This keeps my tank at KH2, GH2, perfect for breeding soft water fish.

Recommendation: Pick your target GH, probably around 4, and reconstitute
your
water with RO Right to meet that target according to the label directions.
4KH
is also a pretty good, as it gives you a good buffer for future CO2 usage.
If
you have evaporation between water changes, refill with pure RO.

Here are two really good discussions of the relationship of KH, CO2 and pH
from
Google Groups:


http://groups.google.com/groups?hl=e...readm=1f2t2ny.
q0nqcgswq090N%25wuggamom%40yahoo.com&rnum=7&prev=/&frame=on


http://groups.google.com/groups?hl=e...readm=7ed3be%2
4t3a%241%40nnrp1.dejanews.com&rnum=10&prev=/&frame=on