this is the perfect place for doing wc
I have a floor drain behind my service counter so when I do water changes I only ever have to give a pull on the syphon for the first tank and then I maintain the vacum from there on in by crimping the hose from tank to tank.
All totalled it takes me about 5 hours to do the wc, I do them on sat as that is a day where almost nothing happens here for business but coffee and drinks.
One thing about wc here is that i have a hand wash station where I hook up the hose attachment for refilling and since i have a floor drain NO BUCKETS ;0)
I do have one little trick that I do when I do them that I will share here since I am pretty sure that we each have our little tricks of the trade. For me it's funny but my career as a chef has given me some interesting ways of doing fish keeping, at any rate here is my trick.
I use seachem prime as my water treatment and I use this method, when I am about to do the change I take 1 capful for every 50g in my tank and I pretreat the water with prime by slowly pouring it into the water that is flowing out of filter spout but make sure not to actually get any in the filter media, then I pull out the 30-50% water and refill adding the appropriate amount of prime to treat the water which is being replaced ie:25g=1/2 cap.
I figure it this way, a water change has to be somewhat of a stressfull thing for the fish and prime is a treatment that can be added in a 5x dose if you ever needed so a 2x dose at water change time can't hurt, further I pretreat the water so that there is fresh prime in the remaining tank water so as to counteract the addition of untreated water though the new water has prime added to me its not the same as having fresh prime full well circulated already.
While this practice of mine for waterchanges may not appeal to many or any, for me it works and I thought i would share it.
Oh one last thing, one of my wc times i do a double change on the really big tanks so I do the normal one on the sat, then I do another on the following monday. One other way that I keep track of stuff like filter maintenance and filter cleaning is to take a wet dry marker and write the date of media change and filter cleaning on the side of the tank it erases easy and keeps thing organized.