水草情迷

Thank you for your help, guys. My plants are excellent now, or at least up to my own standard. Andy, fishfan, simon, octoct2010, gwu, or someone I didn't listed gave me lot of help.
Now, the plants are having million of bubbles very stable. They are awake! Its good to have my confident back before I receive my new 4' tank tomorrow.
What the problem is>
My current tank has about 23L of water. I use T8 15Wx2, which is not enough and the plants looks stop growing. Since I try 15Wx3, plants looks good again.
I did some testing before with water quality, co2, water flowrate, all goes to the wrong direction. I didn't consider about the lightering power, as I thought 1 watt/L is the standard.
Once I received my new 4' tank, I will post it out.
just a few question about the equipment, please see from my other post.