CO2 reactors.

[BigA]

Just thought I would ask what does everyone think of the different kinds of CO2 units. Fermentation or Compressed Gas? Manual or Auto? Are different brands more prone to be faulty? What does everyone use in their planted tanks? I want to put one into a tank that will be planted and be home to some discus. The tank is 36" x 18", and 24" high. Any advice? What amount of CO2 would be good for nice growth? 30ppm? More? Less?

[jvision]

I'll tell you what I do...

I don't own any test kits anymore (if I do, they've been in storage for years!).

I got my first pressurized CO2 system a few years ago, and I will never go back to DIY (except for small tanks, but I usually just use Excel, then). I have a small Paintball canister and a 10lb tank - both are great. Just get a regulator that works on your size of tank.

If you have between 2-3 WPG, you're going to want around 2 bubbles/sec - more if you're going with more light. I bubble my CO2 into the INTAKE of a powerhead (not the venturi hole) - I've found the best success this way. But, there are many other CO2 diffusors that work well. There is anecdotal evidence that fine mist is absorbed even better than dissolved CO2.

When you go with med-hi light + CO2, you're going to want to firtilize. I use the Estimative Index method (I'm lazy).

The trick to success with planted tanks is to start w. more plants then can fit! I'm serious - plant it as thick as you can with fast growing plants right from the start. Most people start slow, get algae problems, then quit. If you start with an heavily planted tank from the start, your chances of success are way higher!

As the plants become established (good growth, roots, etc) you can slowly replace the fast-growers with the plants that you really want.

Edited March 15, 2007 by jvision

[werner]

Pressurized is the way to go. I use a reactor to dissolve the CO2. The ceramic diffusers are good for making a fine mist, but need frequent cleaning and are not usually suitable for larger tanks.

20-30ppm of CO2 is a good goal. An easy way to achieve this is to remove some tank water and let it sit for a day. Measure the pH. Then add enough CO2 to the tank maintain the pH 1 degree lower. That gives approximately 30ppm of CO2. If you're going to throw some cash at this, a pH controller is a really nice toy to have (no messing with bubble count, etc.)