Today I brought home some new loaches!

I want to eventually add them to my 55 Gallon community, which is virtually empty for its size, having only 3 white tetras, and 2 weather loaches in it.
I read today in my new book LOACHES-A Natural History and Aquarium Care (Just got it today after waiting about a month, I'm so excited!) That too few tankmates can stress out your loaches. So I figured it was time to introduce them to some buddies.
They were all labelled as weather loaches, but I realised on first glance that only one really is, the others, I believe, are either oblongas, or pangias.
Then the dilemma. I have only an established 20 gallon (it already houses 4 kuhlis), a still-cycling 55 gallon, and a 1.5 gallon quarantine. I really want to quarantine them, especially since one of the kuhlis doesn't look so good upon closer inspection, but on the other hand, I hated to put them into such tiny quarters. Well, eventually the quarantine won over. I have them in the tiny tank but now I wonder how long to keep them in there, and while they are there, should I be doing daily water changes?
I have a line on a bit bigger quarantine which I may buy tomorrow. But if that falls through, how do I maintain this quarantine tank and still be fair to my new pets?
Any help or advice will be much appreciated!
soul-hugger