Clown loach looking sickly

I bought three clowns in August, they've been living in a 20gal alone until a couple days ago when I added a pair of german blue rams. [Side note: yes, I know the clowns will outgrow this space. I plan to put them in my 45gal once they get a little bit bigger]. They were treated for ich not long after purchase, but have been in good health since. I've observed some black spots on fins, but I was told this was normal.

For the past couple of days, one clown has been hiding most of the time sandwiched between leaves on a plant. I coaxed him out today and examined him - it appears he hasn't been eating (his belly looks hollow and I haven't seen him coming out to eat much) and the edges of his fins are a little bit white. He just looks sickly, too, especially when compared next to the other two loaches.

My hospital tank was broken a week or two ago when my father tripped and went flying, but I've kept the filter from it going on the 20gal so I can go out and buy a new one and get it set up for this poor loach. I really don't know what to treat him for (or with), and I know these symptoms could be indicative of a few things, which is why I'm asking for help.

Thanks.

[CRaZeeeBiTcHisH]

when you say his fins are white--is it white and fuzzy, white--pale looking?, or does it look like his fins are eroding? look up some pictures of fungus, fin and tail rot, and see if either looks like what you have...let us know if we can help any further