I use a couple of those big blue drums, filled with water, in the fishroom, so the temp is the required heat all ready.
From this I have a long 3/4" plastic pipe, with pump attached, to refill tanks.
Removing: I hand syphon using a gravel cleaner, but as a watch has to be kept for any elusive fish, the water goes to a bucket, and then out to water the garden or lawn.
I have got provision for the waste to go to an internal drain I put in, this is primarily used when empting the bigger tanks.
Alan