upgrading to 40 from 20

[RABENA]

I asking for help changing my 20 long finally to a 40. any help will be greatly appreciated
thank you ?

 

[gilpi]

What help do you need?

 

[RABENA]

start with the filling of the tank can I siphon 10 gals a day for 3days off this 20

 

[flitabout]

Just to let you know the bb( benefical bacterial) doesn't live in the water it lives on the hard surfaces of the tank like in the filter sand/gravel substrate, plants, rocks and driftwood and on the glass. You can do it but I'm not sure why you would.

 

[gilpi]

start with the filling of the tank can I siphon 10 gals a day for 3days off this 20

Not sure I understand this.

Let me ask you.... in your 20 do you have an established or cycled filter running? If so, just put that filter in the 40 and you're ready to go, does not matter if you take water from the 20 or fresh treated water, I would rather use fresh de-chlorinated water.
Not sure what filter you have but you might have to upgrade the filter or add another one depending on what you have now.
You might want to let us know what fish you have, filter etc.