I'm not so sure about how easy that would be. Slot processors must have drains to empty the slots, ideally a drain for each slot. Trying to lift an aquarium large enough for 16x20 prints that is full of water is inadvisable.
Hey Jerold,
the OP has stated that he doesn't have access to a sink in his "darkroom", so he could technically have the "slot processor" on a rolling cart, if he wanted.
but yes, if he wants to print 16x20, this could be a problem, well probably more than one.
1. he has stated that due to living in NY, he has cramped quarters. this is understandable, unless you're a Trump family member. but he has stated he wants to print 16x20?
I print 11x14, and would like the option of 16x20, ideally.
if he doesn't have that much space for a darkroom, or at least easy access to a sink, where is he going to store 16x20 prints?
2. I've never been to NYC, but I've heard from friends that the dumpsters there are a literal goldmine for those willing to search. If you find the right ones that is

. So furnishing a fishtank shouldn't be THAT hard, especially now with craigslist, ebay and Kijiji(another craigslist) at his disposal.
3. IDEALLY, having a drain for each slot is nice, but definitely NOT necessary. Buy a plug-into-the-wall 115v waterproof pump, and just wash it out between chemical changes. Shouldn't be any problems with that.
Just go to Home Depot/Lowes/Ace Hardware, and ask to see their plug-in water pumps.
I'm not trying to argue, just asking the OP to maybe use his noggin a bit more than I've personally seen, or read here so far.
I'm not a book-smart guy, but investing $100 to build your own slot processor is a nice weekend project. IF he really wants to print THAT BADLY in his little NYC apartment.
just my humble $.02
-Dan