Bob A wrote:
3-4 months back I did a LOT of research on the proper methods of good plant
health, with the intent of heavily planting. Things then drew me away from
this for a while. Now I have the All-Glass 110w PC (not on the tank yet), I
have PMDD consisting of K2SO4, KNO3, and MgSO4 (separately). I have read
and printed out the pages on thekrib on PMDD.
Are you missing the actual trace element fertilizer component of PMDD? Usually,
it's something like Plantex CSM. Or do you just have the three macro chemicals?
I have Tropica Master Grow
and Flourish (so far I've only been using Flourish) and 1/3 Flourite
substrate (along with 2/3 pea-sized gravel).
As others have pointed out, TMG is a complete fert product from Tropica, which
includes Iron and Potassium. Flourish is a less complete product from Seachem,
intended to be used with separate Iron and Potassium. Neither includes Nitrate.
Pick one, give away the other. Or pick PMDD and give away both. You get the
idea.
I should add that I'm now using RO/DI water, due to contaminated well-water
and getting tired of "importing" water from 5 miles away in a trash can. 
I'm using RO Right, a touch of baking soda, and Kent Essentials.
I use pure RO water, no tap water. To target GH2, KH2, my recipe for 20 gallons
of water change water is:
2 teaspoons RO Right
1 teaspoon Baking Soda
This is used for a 30% weekly change. KH drifts down slowly (in my case, a bit
less than half a point a week), which is something to watch when injecting CO2.
Phyl suggests using a regular airstone with no
reactor. I think I will put an airstone next to the intake of my power
filter.
CO2 is a simple thing. If it drops your pH, it is working. If not, you need more
CO2 or a better reactor/diffuser scheme.
For DIY CO2 on a 55 gallon tank, consider using a pair of 2 liter soda bottles,
and changing them on an alternating 10 day schedule (Day 0: Change bottle A. Day
5 Change bottle B. Day 10: Change bottle A. Day 15: Change bottle B) This is a
little more frequent than some schedules suggest, but will keep your CO2 level
up. You could also start with a longer schedule and tune it based on measured pH
level.
Read Chuck's page for more info:
http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm