What's the big deal with CO2?

[jibboo]

quick question here ... i see lots of people stating that CO2 is a must if you have high light in a tank.

So, my situation: 55g, 160w of light, lots of plants.

I've been running for 4 months with my plants doing quite well. I don't have any CO2 running and everything appears to be working out well.

So, why does everyone suggest using CO2? I guess I'm not seeing the point of it from my experience. Now, maybe 3 wpg isn't considered a high light tank ... can anyone shed some light on the subject?

TIA

 

[malkore]

then you've been extremely lucky.

in high light tanks, the plants grow so rapidly they'll use up the available CO2 in the water. this stunts their growth, and consumption of nitrate and phosphate. that tends to lead to algae blooms.

CO2 injection makes it much easier to control a high light tank, because you never run low on available CO2. Typically you only see algae problems if nitrates and phosphates get out of whack...and even then they usually have to be way out of balance before you see any significant algae formation. On the other hand, in 24 hours a non-CO2 injected tank can go from perfect, to horrible greenwater if you get a little off on your nutrient balance.