With a 250 I don't think that's enough light. However if you have a sealed room with no vents you need it to keep up the level of co2 just for growing. If you can vent the room it's better.

With co2 you need alot of light and bring the temps up into the low 90's. And keep the water cool. That's the problem, keeping the water cool.

Another thing is co2 can displace the air and flood a room or house making it imposible to breath for animals and people. So be very careful if used in a people living area. It's odorless and tasteless so you don't know it there.