Do you have to have Co2 in a planted tank?

[ScottVinVA]

I have a 26gal tank that is semi planted. I hope they grow to fill in more but do you need a CO2 feed for heathier plants?

How much does a real setup cost?
How much can you do a DIY setup for? I have a paintbal tank I can use. Just does not have a flat bottom.

Thanks

PS Here is my tank: http://www.veirs.org/photos/tanks.jpg

 

[electrikat]

You only need co2 if you exceed 2 to 2 1/2 wpg of lighting. There are some very inexpensive to build diy setups out of 2 liter coke bottles. Do a search on here and on google. They look very easy and cheap to build.

 

[travis simonson]

Yep, electrikat is dead on. CO2 makes everything much easier and your plants will love you for it, but if you don't have over 2 wpg of light it is not a necessity. A 26G tank would be fairly easy to set up with DIY CO2 and it's cheap, so you should look into it. Even low-light tanks can benefit greatly from CO2. CO2 is excellent for giving your plants an advantage over algae at any wattage level I've read accounts of people with 1-1.5 wpg tanks using CO2 who haven't changed their water in 6 months. I can only dream about that kind of ease of maintenance