CO2 and/or hard water
Well, I've been working on setting up my planted tank and it is coming along nicely. So far I have a 30L with Flourite substrate, a 96W compact flourescent light fixture with a 67K bulb, and NO CO2. We happen to have extremely hard water out of the tap, and I generally keep fish that are comfortable with this to avoid the expense and/or headache of changing the water.
I had not given this much other thought, but my husband went to an open house someone was having yesterday. The man had something like 40 planted tanks that looked amazing, and he has kept planted tanks for many years. They (my husband and him) got into a discussion about my tank, and our hard water. It was his opinion that I will never need CO2 because of our hard water because the hard water is in essence carbonate hardness which he explained was basically what CO2 attempts to accomplish.
I was astonished because I have never heard this before, but he had 40 planted tanks that were thriving and he did not use any CO2 at all. He had soft water and simply buffered the water to acheive the carbonate hardness.
So, anybody familiar with this concept already? What do you all think?