You people are crazy...
I use a siphon and a 5 gallon bucket :3 My 10 gallon takes me 5 minutes to do, LOL! My 20 gallon took about that long as well. For a 45 you'd make 4 trips for half the tank water :P It does slosh, so if you're near the top, I would suggest a lid!
Buckets are like 3$ and their lids like 1-2$. Siphon depends on make, model, and size, but mine was 8$.
On my way to work, can chat for like 30 mins-ish...
Kaida- CT Female 2.5 Gal.
Julep- HMPK Male 2.5 Gal.
Fandango-HM Male 10 Gal.