Watch for this thread to evolve on the subject of water change volume. Take notice of who is posting in here.
http://www.reefcentral.com/forums/showthread.php?t=2336061
These are seasoned dudes. Bills reef practically owns this site if not literally lol I don't know but the point is, if anyone posts something dumb in this thread, or in the chem forum, they will experience various degrees of justified and hearty evisceration that will make them not want to post again
I get my willing share of beating by inserting myself into chemistry arguments about peroxide use while not being a chemist...but in the end, I want the staunchest least crap taking people evaluating what is done or typed and if these dudes don't shoot down the properly done large water change then again you have powerful evidence mainly backed by their years of experience.
Nobody in that thread except the guy with the little tank bothers or needs to do large changes, but see what they say about the science of doing so should someone have the need. Effects on bacteria are discussed and challenged, basic chemistry questions, the common reasons not to do large water changes are evaluated by powerful aquarists.
Its my opinion most of these guys run their tanks with such a command that large water changes aren't needed, but you can tell by reading if it needed to be part of their repertoire they wouldn't bat an eye to pull it off. Just know that large water changes, even back to back ones that really flush your system well, are great. Try to engineer ways to do them less so you can evolve the hobby, but if you get off track, they work. They correct many things from the fearful possible ammonia spike, to the day you accidentally overdose 2 part and wonder what to do, to the day some friend accidentally dumps 3x feed into your tank.
Having the power to do them accurately and with command is the most important aspect of a large water change, thats your reset button.
No matter what anyone says my reef will get them weekly its come too far to change up now, but I'll enjoy watching other techniques evolve as people use their $$ as the testbed and find ways to help us conserve reef water better than we do currently.
If i owned a three gallon tank I prob would not do all of it entry single week, too much water. But I'd do prob 50-75% on lazy weeks and then a 9 gallon back to back power cycle at least every 6 weeks for starters, that's not too much work to accomplish something that would allow me to sustain a thousand dollars worth of frags and eventual colonies. Imo its preferable to all the tedious machinery that may work well for someone else.