Thank you both for your great input.

The issue is that in my tank it seems that I need to sustain a bubble rate
of at least 1 bubble per second to get that. I did find a recipe that gave
me that output but it died after a few days. Could have been a leak.

I don't mind changing the bottle every week.

-Frank

"Marcus Tait" wrote in message
...

You still need the correct levels of all the nutrients (inc CO2) in the
water its just that you will be adding less to keep it at that level.
So you still would be better with 20-30ppm of CO2 in the water whatever
the
amnount of light you have. It would be the same with any nutrient like
potassium which yo would want to be approx 20-30ppm, the plants would just
be using less of the nutrients and you would not have to add as much to
keep
it at that level.