Seting up a new crypt tank, 3 questions.

[Ted Backman <tedb at valvesoftware_com>]

I recently moved offices and am now in the process of setting up my custom
68 gallon aquarium again.  I'm going to try to create my own version of the
cryptocoryne and R. heteromorpha aquarium on page 93 of nature aquarium
world 2.  

At the moment I'm trying to decide on the following, what substrate to use,
whether to bother with my CO2 system or not, and if C.parva will grow under
two 36 watt CF bulbs (with reflector).  

I recently setup a test 10 gallon with some of the flora base soil substrate
and a good mix of crypts, it's showing good growth so far, and I'm impressed
with how little the soil affects the water column.  This stuff is pricey
tho, (25 buck/ bag at my LFS).  Might there be a more cost effective
solution?  (potting soil under sand ala walstad?).

I'm going to shoot for a good sized shoal of heteromorpha, (fifty or so)
which got me thinking that supplemental co2 would be wasted on crypts.  In
the previous incarnation of this tank, I did notice that my C. Undulata did
have more vigorous growth with the CO2 going, (given I was using a much more
intense 250W MH pendant).  And the fish load wasn't as heavy in that
incarnation.

My last question is this, the tank is 18 inches tall, and has a really nice
2/36 watt CF fixture (with reflector) near the front of the tank, would this
be sufficient light to grow C. parva to the density shown on p93 of NAW book
2?

I know that's a lot of questions for one mail, but, hey, I'm a bit excited
at the moment.

-Ted

P.S.  Last time I dug around, both Delaware Aquatic imports and Aquabotanic
list C.parva as something they stock regulary, any other suggestions on
where to buy?

Thanks!