For water changes I've gotten a 50 foot vinyl hose that I use to drain the water from the tank directly into my bathtub (you could also drain to outside garden too, but I'm on a 2nd floor apartment, so you could imagine the chaos that'd be out my window). I put a fine strainer in the tub under the draining end of the hose for "accidental fish water slides" but haven't had that issue since I usually use old filter intakes on the part inside the tank that's smaller than my fish, with exception if the pangio loaches, I don't trust them buggers not to get into anything.
To refill, I use a drinking water safe garden hose, (I use a 25 foot one as my kitchen is located middle of my home to where all my tanks are), attached to my kitchen sink with an adapter. I dose dechlorinator for full tank volume after draining the tank before refilling. Utility clamps are great to clamp hoses to side of the tank to drain after vacuuming and while refilling.
Cheaper than a python system and less back breaking and time consuming as buckets are. I've got arthritis in most my body, I ain't sitting around draining 300 gallons plus of water a week.
To know how much hose you'd need, take some yarn, spread it from your bathtub and kitchen faucet to your tank with some slack on it, cut it and measure that cut portion of yarn.
I've got multiple tanks, but even for 1 larger tank this method would be better than buckets.