If you can manage to get the bag open but not spilling inside a bucket, you can take your gravel vac and get it going, tie a knot in the hose to make it just drip, put the hose in the bag so tank water is going in the bag slowly (like dripping, not streaming) Let it overflow or get close to it, stop the water flow, and then I personally would float the bag in the tank for a while too. If you have any air hose for a bubbler you could use that instead of the gravel vac. It would be a lot easier to make it go slowly. But you need a way to keep the hose in the water (I use a spare holder that i use to run the hosing behind plants). And you need to start it with your mouth. If you have the air tubing, use that, if not, the gravel vac will work, just need to make sure you can get the water to just drip out.
Just start watching at like 8:16
[video=youtube;leLjnpuiPGQ]http://www.youtube.com/watch?v=leLjnpuiPGQ&feature=pyv[/video]
