Excel will definitely help because you're probably still not going to have a lot of CO2 in your tank. I loved the ladder thingie in Hagen's system but I didn't like the container since it was so small. To put things in perspective, I have a 25 gallon tank that I had two 2-liter soda bottles on (going into a powered internal reactor), filled with slow growers and no stem plants. I still had problems getting enough CO2, causing algae problems and poor growth of my plants. It wasn't until I went to pressurized that my tank took off. But of course, pressurized systems are a bit of an investment so not everyone can just get everything they need right away.
If I were you, I would think about adding another bottle of DIY CO2 and supplement everyday with a little Excel.