What's a Dtps.?
 

I have one miniature orchid that actually has a name: "Dtps. Liu's Hua Lien Star 'Montclair (P. Sogo Mini Dog x Dtps. Anna-Larati Soekardl)." It is growing quite differently than the other phals, and hasn't done very well in my house. The leaves are very small, and it hasn't bloomed since purchase a year ago, but it is putting out lots of healthy looking aerial roots. Time to repot, can I be doing something different? Is a Dtps something different from a phalaenopsis? And do I try to stuff all those aerial roots down in the potting medium? I appreciate all the expertise and helpful suggestions here, thanks in advance!:)

Abbraviation for Doritaenopsis, a cross between Phalaenopsis and Doritis.

Whimgrinder is correct. But they are very similar and there are many Phal/Doritis crosses to the point that they have all just been renamed as Phals. Culture is the same. The RHS has been reclassifying and grouping many orchids in the last few years and I think this is one of them. You can just refer to it as a Phal and grow it as such. Some Phals are more prone to growing air roots, but if the media is old and compacted, then it is time to repot. You could soak the roots and try and gently wind a few of the aerial roots into the pot, but they are fine out of the pot too and give a nice tropical orchid look (in my mind). I like clear pots with good holes and a mix of moss and medium bark. But others do well with different mediums depending on their conditions, so do what works best for you. Don't use a pot that is much larger than the roots need or it will stay wet for too long and cause root rot.

The genus Doritis has been reclassified as Phalaenopsis, so they're all Phals now ;)

Some phals are also larger/smaller than others. There are many "species" phals that are also used in breeding, and sometimes you also get a mix of one in there. A plant can have dozens of "parent" plants down the line. A plant doing badly, say, smaller leaves, rather than similar size or larger than what it had when you got it should be given either more/better sun, more/better water, or more/some decent fertilizer of the sort reccommended. Plants grow (aka grow cells) using building the blocks of water, sun, and trace minerals.