There's very little beneficial bacteria actually floating around in the water. Most of it is on surfaces like sponge filters, rocks, sand, etc. If you had your biowheel in your sump or tank for at least 4 weeks prior, it should be seeded. As far as the water volume, you can always use a pitcher or some other measuring cup that is marked and fill it up that way. I used a 1g pitcher and after every gallon, I made a mark with a sharpie so I would know exactly how much is in there.My bucket has the water measuring Mark's I have no other way to measure the water. So that part I have no choice but to *wing* it.
So if i make a new bucket it wont have the tank water, it will be freshly made. Wont this force an ammonia spike due to the water not being cycled? I cant afford to throw 200$ of bacteria at a bucket in gonna dump out daily. I'm useing a bio wheel that ran in my tank for 2 years. So should have plenty of bacteria, but I dont trust it.