Thank you for your responses. Yes, I do fertilize them regularly. But I don't have a fish, seems like that was a good idea!
You are probably right about the repotting, at least on some of them. The Sharry Baby I repotted right away after I got it, into a pot that seems plenty big. Even after 2 years there seems to be plenty of room in the pot (6 inch pot), but all on one side. It seems all new growth crowds in behind the old growth, even though there is plenty of space in front of it. Not sure how to get it to come in more evenly all over. Should I just take it all out and place it more central in the pot? Or just take it out and use the same pot with new potting medium, since they say not to use too big a pot? (although the potting medium still looks pretty good).
The Dendrobium and the Phalaenopsis, I think should probably be repotted. I've been procrastinating, worrying that I'll repot at the wrong time. I'm not sure how to know if it is at the end of the growing season, or just starting, when it hasn't bloomed for awhile. Both of them seem to have healthy new leaves coming in. It used to be that my Phal always had three leaves. When the next one started coming in, the first one would die and drop off, but now it has 4, plus a very new one coming in. A year ago something seemed to be eating the edges of the leaves. It was driving me crazy since I couldn't see anything on the leaves, but I finally washed them off carefully with water and it seemed to take care of it, although ever since there are three or four gouges in the leaves that I have to put up with till those leaves finally die off.
I hope you don't mind all these questions, it is so great to finally find a place to get some tips on whether I'm doing it "right"!