Without doubt one of the most important additives for a lush planted aquarium.  All aquarium plants demand CO2 for growth during daylight hours and give off oxygen at night.  In the aquarium some CO2 is provided from fish waste, plant debris and uneaten food BUT NOT NEARLY ENOUGH.

The supplementing of CO2 in the small aquarium need not be an expensive or complicated affair.   An new alternative to a CO2 system is liquid TNC Carbon, an effective and simple to use carbon source.  It can be used in conjunction with CO2 injection or as an alternative.

CO2 can be dangerous to fish and therefore needs monitoring.