Dundadundun,
are you pumping co2 thru the air pump? no
or increaing circulation to help air/gas exchange? not really, but yeah. i've actually increased my co2 level with a simple airstones and pump by utilizing excess in the atmosphere. thanks tom barr! i'm sure it helps with air exchange also and i have moved a couple of the airstones strategically to increase water movement in stagnant areas.
while adding CO2 may not be needed in many set up's,. the addition of CO2 is beneficial to all planted tanks in general. of course... if it's stable and levels are controlled
in high light/hitech tanks Ferts, lights on timers and CO2 all work together.same with "low light" ime. i do believe low light success is the question at hand considering the current lighting.
you can get by without CO2 addition in lower light tanks. but be watchful of algae which can become a problem.really? i've experienced quite the opposite.
but can be controlled with controlling light on timers.if co2 causes your algae why not limit co2 instead of light? seems simpler and common sense to me. i'm not saying necessarily cut it out altogether. once again my smaller tank runs up to 15 hours of light in a single day and i get better circulation out of my air pump than my filter (ie: very little). i keep my ferts and gh stable and everything's awesome. btw, that is on a timer... i cheaped out and got a no frills mechanical and the settings are all whacky. instead of fighting it i don't fix what's not broke.