Hi kmjorge! Welcome to R2R!
I am myself a new saltwater hobbyist (at least in personal practice) and live in Gaithersburg. I live on the northern side (which is "technically" Damascus), so finding a good LFS was tough. There are two that I currently have been working with as I feel it's good to diversify your supply chain and broaden your community to solicit advice and guidance.
I bought my tank (Pro Clear Prostar 150 V2) and most of my accessories from Aquatic Creations in Ijamsville, MD (on 355). The proprietor there has been in the business a long time and is very responsive. The store hours can be a bit tough to make work depending on your circumstances, but I have been happy with my experience there. I am not sure of the QT services, but I do know that they use UV sterilizers and dose copper.
I have also been to Fintastic Aquariums of Frederick and picked up my initial livestock there. They tested my water for free and spent time with me each and every time I was there. It's a cozy location, but it's full of tanks and has a wonderful variety of livestock. They usually post once a week with some of the new shipments they receive. This store also doses copper. They do not QT directly there at the store, but when I asked they said that there was a 3rd party that could do this for you. I didn't explore that too much, but I'm sure if you called them they would expand on that a bit more.
I haven't ventured out much from those two locations. I wanted to keep my trips to the LFS close to 30-ish minutes, which these satisfy that desire (on most days - traffic in our area can be somewhat unpredictable).
Hope this helps!
