thats all i use, 2 t5 4ft bulbs, im plannin on gettin the hydrofarm 4ft light stand aspecially for t5 lights 2 bulbs.. but yes your answer, this is more then enough for seedling to get going, as long as its only about 2 to 3 inches above the seelding tops.. heres a little info on some fluros and their lumans..
- The average lumen output of a 40-watt T12 is 2800 lumens, about 68 lumens per watt,
- A 32-Watt T8 bulb yeilds 100 lumens per watt and cracks out 100 average lumens,
- A 54-watt t5 throws 5000 average lumens, which means it produces 92 lumens per watt,
Hope This helps,
Good Luck,