Well, I don't know if it would do that much good.
I've heard a lot of people recommend it, but others say the bacteria is not really free floating so it doesn't matter. I probably wouldn't mess with it. I have started a 20 gallon, a 30 gallon, and a 55 gallon this way with no problems. Just keep testing the water- I had a small and short-lived nitrite spike in the 55 gallon that required a PWC
, but then the tank cycled in 3 days. I don't think yours will cycle this quickly, but it will be much quicker than starting from scratch.