I don't know what size tank you have but honestly that isn't a good CO2 system. You will end up spending a lot of money on refills and IMO they aren't that efficient. Depending on the size tank, your lighting, the type of plants you have you might want to look into doing DIY CO2, a smaller paintball CO2 system, or even higher dosing liquid carbon such as Metricide 14 daily.
I asked a similar question when I purchased my Fluval CO2 setup and got a similar answer from Rivercats.... And she was correct. I ended up having to buy a 3-pack of the CO2 refills every 5-6 weeks. At $18 each, I spent more money in the long run than if I had just purchased a "paintball" systems in the first place (which is what I ended up doing last month anyway).
If you can, then I would recommend returning it and putting the money toward a better set up. My 20oz paintball CO2 tank was $20 (plus $8 to get it filled locally), and the Aquatek regulator was $90. Look in Amazon or EBay.
Any advantage of paintball system versus Excel?
How about surface agitation? It will affect paintball system and make co2 disappeared?
During the day when CO2 is running you want little surface agitation as that will indeed gas off the CO2 your adding. The advantage of CO2 over Glutaraldehyde (Excel, Metricide 14, API CO2 Booster) is you will get faster, fuller growth. Glut, liquid carbon will give plants give a big leg up over not using anything and will increase growth and photosynthesis but not as much as CO2. I run tanks with CO2 and some with just Liquid Carbon.