2nd timer,
There's actually a pretty active
marine aquarium club in the DFW area:
http://www.dfwmas.com/
They also have a web board at:
http://reefcentral.com/vbulletin/for...php?forumid=58
I used to live in Irving, and typically went up to Dallas North Aquarium up in Carolton. They're ok, have a decent selection, but I thought they were too expensive and the advice really depends uppon the person helping you. I also don't like the fact they keep a selection of small sharks and other exotics (found a couple of octipi there once), and will sell them to any idiot. (I like they have a selection, kinda nice if you are pretty advanced, but I frown on irresponsible keeping, which selling such things to newbies really encourages. ) Since it was so expensive, I tried to buy most of my stuff on-line, but if I needed something right away I would hop over there. I bought all my water, both salt mixed and topoff from there in 5 gal tanks, so I typcially stoped in once a week to get water and browse.
There's one in Irving, Saltwater Paridise. (on O'Connor) I went in numerous times, but I never bought anything there. Everytime I went in they seemed to be having problems with ich, cyano breakouts, and other types of things that show significant water quality problems. They are pretty new, so maybe they are just having to get some kinks worked out. I recomend checking in with them periodically, but make sure you are happy with the water quality before you buy. All the tanks there are salt, but they have little selection in dry goods.
There are more LFS in the area, but those are the only two I checked out durring my 1 year stay in Dallas.