Originally Posted by jwm5
Will having CO2/ferts expand your effective light range. Probably confusing statement, what I mean is if I have a low light tank with ferts and CO2 will I be able to potentially keep moderate light plants in the tank? Or are light levels locked, low light plants can grow in all light levels, as if it were an upward ladder, plants can use light levels up the ladder, but never down the ladder, ie high light would never do well in moderate/low light.
With the increasing use of CO2 on planted tanks many people have found that plants that have always been classified as "high light" plants actually ARE more dependent on CO2 than actually very high light levels- so I'd say the answer is yes- there are many plants that may do quite well in a moderate or even low light setting if they are also supplied with adequate CO2 and fertilizers. They may display different growth patterns and coloration than when kept under higher light, but many will still grow very well. This forum is a great resource for researching others' experiences with specific species in different light and nutrient conditions, which can give you a good starting point.
That being said- the bottom line really is that every individual tank is so different that you won't know how well you can grow a plant in your specific setup until you try it... I, for example, can't keep hornwort or anacharis alive for the life of me, despite their reputation as "easy" plants and my success with other much more "difficult" species LOL