20 watt bulb, 18 watt ballast???

[jaymasta]

Well I want to add 2 more bulbs to my aquarium, now walmart has a nice ballast and fixture for 9bucks but it says 18watts max, the bulbs iam going to put in are a powerglo, and a flora glo bulb, they are rated at 20watts will this cause any issues or problems other then the bulbs only putting out 18watts instead of 20. I could get the 20 watt setup from my LFS but they are 45 bucks a piece so its like $100 vs $20.
thanks in advance guys

 

[hondamx]

Buy it and if it doesn't work bring it back

 

[Jericho]

It is not a good idea to put a larger bulb in that fixture. It may burn out the balast or cause a fire.