It kind of feels to me that Aquariums are a dying hobby in Austin, or if not dying - shrinking. Even before Covid, corporate aquariums were taking an economic hit. That in turn hit the aquarium service industry. I know we gave up our office tank (It was probably about a 250 gallons reef). Talking with the LFS's - that was common, it was an easy place for businesses to cut corners - and the service industry was devastated. In all fairness, since I am retired I usually shop during the day. Most of the customers I have seen at Aqua Tec during the day still looked like they were in the Aquarium service industry (4 out of 5 were loading up trucks or vans with water).
Meanwhile, a LOT more people are apartment dwellers than home owners - so the vast majority of aquariums are shrinking. Nano's are replacing full sized aquariums. All the shops are now stocking miniature breeds to allow more stocking in micro aquariums. The reef ready tanks that were in stock are now mostly smaller AIO's. I doubt that was just Austin. I have gone to most of the stores in Austin and San Antonio over the last 2 weeks - I doubt I could have picked up the equipment between all of them to really set up a tank like I wanted (maybe, but it would have been parts here and parts there. There were 2 shops in San Antonio that might have been able to set me up - if I was willing to just use the brand they stocked - apparently Red Sea makes good deals to stores. I did see at least one stocked Apex dealer, and Kessils were availble at quite a few places (abet often if you only needed a single light and did not need a light hanger (or wanted the goosneck hanger and not superior J hanger).
I used to work off of Mopac and Spicewood/Anderson (I was on the Spicewood side of the intersection - the road changed names at Mopad. You have to love Austin and how roads can change names 5 times depending on where you are in the city). I primarily shopped at a store on Anderson across from the Mall (which I don't think is even a Mall anymore) and a store behind the Mall (I don't recall the name of that road). I seem to recall another off of Burnet (so 3 stores within 2 miles of my office - and honestly maybe Aqua Tec was also within 2 miles). I sold excess plants for random livestock (mostly Amano shrimp that had a 1 month 1/2 life in my tank-my kids liked watching the shrimp, so I kept restocking them) and in store credit at the store behind the Mall. It was somewhat depressing when the cube I was saving up for went away when that store mysteriously closed their doors (I had enough credit for the tank, and was already working on filtration) without warning me first. When I tried to rework my planted tank 2x ago - noticed that google maps was not showing the Anderson store (or the Burnet store) there anymore (but I could not recall their names - so perhaps they just moved).
I did not shop much at any of the others much when I lived in Austin . Recently I have been to all of them multiple times in the last month. Aqua Dome is a warm, humid dome with a maze of aquariums in it (but it is a fairly well lit store). Good stock of things I was looking for. Aqua Tek is a better lit less clostrophobic store - but they get afternoon sun and can still get pretty warm inside. River City keeps their lights dimmed, especially in their main room (they have full west exposure - so they are all but tinted black IIRC). They have little hardware - and since they have virtually no freshwater are a somewhat smaller store. There store is L shaped, maybe some inventory is behind the wall in the service area. Tiny Aquatics is in a newish, upscaleish strip mall (La Frontaria). They are fairly packed, but do not feel clostrophobic as they are well lit and well airconditioned. They feel "modern". FWIW their back room is barely bigger than a closet - so limited back stock, and that is packed heavily. They squirmed a lot when I told them I wanted the 60c... It had to be dug out. They had no clue how I recalled actually seeing it the week before. I guess they might have had 2 in storage and had pulled one for a customer and I happened to come by before the customer picked it up. They were adamint that it was not on their floor as they had no place allocated for it. I recalled walking arround it, and that it did not have a price on it - so my bet was it was pulled for a customer. The tank I got was not the tank I saw - I saw one clean, the one I got had been sitting in storage for a bit (dust).