NF:
The following concentrations are stated per my research prior to getting into DIY CO2 (the literature varies but the following I believe to be a rough guide):
2 to 3 ppm - from atmospheric equilibrium
10 to 15 ppm - desirable range for most plants
30 ppm or greater - toxic or lethal to fish
The following criteria I have either observed via experimentation or ascertained via limited input from the literature (and I will use the high recommended fert concentrations on Rex Grigg's site as the basis and term it high fertilization):
2 to 3 ppm CO2 and no fertilization = very slow growth or death of some plants
2 to 3 ppm CO2 and high fertilization = slow growth for plants and more algae than you want to think about
2 to 3 ppm CO2 and 1/4 of high fertilization = slow growth for plants without algae
6 to 8 ppm CO2 and no fertilization = very slow growth for plants but fewer death of plants
6 to 8 ppm CO2 and high fertilization = medium growth for plants but with quite a bit of algae
6 to 8 ppm CO2 and 1/2 of high fertilization = medium growth for plants with minimal or no algae
I have a 30" deep 110G tank.
The 6 to 8 ppm CO2 was attained via a 2 liter soda pop bottle DIY CO2 generator*.
My lighting is:
130W of 7100K CF,
130W of 10000K CF, and
300W of 14000K HQI-MH; and
10 to 12 hours per day lighting duration.
Hopefully the above information will help in "where to start" when you receive your ferts but as each ecosystem is different you will need to experiment, as I have, in order to attain good plant health and growth with minimal or no observable algae.
TR
*This may sound incorrect with respect to previous posts but it is not.
Based upon equilibrium thermodynamics 4 times** as much CO2 injection is required to increase the CO2 concentration from 6 ppm to 10 ppm and 16 times** as much CO2 injection is required to increase the CO2 concentration from 6 ppm to 14 ppm.
**These values are very, very rough approximations only.
