Walking into OSA Aquarium Superstores & Services in Groton, Connecticut, the first thing that strikes you is how immaculate everything is. Reviewers consistently describe it as one of the cleanest fish stores they've ever visited, with pristine tanks housing visibly healthy, active fish. This isn't your typical cluttered pet shop — it's a carefully curated aquatic showroom that staff members Emily, Joe, Sam, and Yian maintain with obvious pride.
The freshwater selection dominates the floor with a large variety of tropical fish, shrimp, live plants, and driftwood. Customers have found pea puffers and other rare species they never expected to see locally. The saltwater section, while smaller, punches above its weight with a strong coral selection and reef-ready invertebrates — enough to earn the loyalty of saltwater hobbyists who previously drove over an hour for a decent marine store.
One reviewer credited the OSA team with helping them successfully expand from a single saltwater tank into maintaining both a thriving reef setup and a planted freshwater aquarium. What truly sets OSA apart is the staff's depth of knowledge. Several employees are cross-trained at nearby Mystic Aquarium, and it shows.
They'll test your water on the spot, help diagnose sick fish, recommend compatible tankmates, and identify corals with confidence. Multiple reviews mention Emily's reef expertise and Sam's freshwater knowledge by name, and customers consistently note that staff never try to oversell unnecessary products. Prices run on the higher side — multiple reviewers acknowledge this — but most consider it a fair trade for the quality of livestock and caliber of guidance.
When you're buying fish that look genuinely healthy and getting personalized care advice from people who clearly love what they do, the premium feels justified. For aquarium keepers in southeastern Connecticut, OSA has become the local store that makes the hobby feel supported. If they don't have what you need in stock, they'll order it.
Just bring your credit card.
Olivia K
13 reviews
Staff are very knowledgeable and kind. They are more than happy to help novice aquarium owners. I received some java moss and good shrimp tips from a very nice lady.
Eric Offermann
23 reviews
Beautiful fish store, great selection of fish, plants, tanks, driftwood, etc. huge selection of freshwater fish and a smaller saltwater section, with tons of coral to choose from. The fish all looked healthy and the tanks were all very clean. The staff was also very friendly and helpful.
Kayla Parent
OSA Groton is hands down the cleanest, most beautiful fish store I have visited since I started this hobby 4 years ago! The first time I visited, I never went anywhere else for my fish keeping needs. The staff (Emily, Joe, and Sam) are all extremely helpful, knowledgeable, and kind. They recently helped me in treating some of my fish when I had exhausted all efforts, they did so at the drop of a hat no questions asked. Mostly the entire staff are cross trained at Mystic Aquarium, I wouldn’t trust anyone else with my babies. Thank you guys so much for everything! I wouldn’t trade you for the world and I’m so happy to have finally found a fish store that genuinely cares. *** HIGHLY HIGHLY recommend*** You will truly not find any better than them❤️
jonathan nixie
2 reviews
In southeast Connecticut, there are very few quality options when it comes to local saltwater fish stores, and I was used to driving over an hour just to find a decent one. I was honestly shocked to find out that the best store around was right in my own backyard. The team at OSA in Groton is absolutely outstanding. Emily is incredibly knowledgeable and always on top of everything—whether it’s dialing in water parameters, identifying corals, or helping choose compatible fish, she’s an amazing resource and always happy to help. Sam brings an incredibly welcoming and friendly atmosphere to the store. He always greets you when you walk in and makes you feel genuinely excited to be there. His extensive freshwater knowledge has been invaluable, and thanks to the entire team, I’ve gone from running only a saltwater tank to successfully maintaining both a thriving reef tank and a planted freshwater setup. The staff here is truly top-tier, passionate, and clearly cares about their customers’ success. I can’t recommend OSA enough—if you’re anywhere nearby, this place is 100% worth the visit.
Kit Hastings-Kort
4 reviews
Excellent service! Excellent displays! Excellent variety! But the most important thing to me, is how Sam was able to help me. I’ve been in other stores where I was completely ignored. Emily also was working very hard! Thank you for taken care of this beautiful store. That was my first time there, but I will be back. It’s worth the 55’ that takes me to get there.
Hi Fonitics
66 reviews
great customer service but too high prices of products
jason pelchat
21 reviews
Horrible owner, these people don’t stand behind their product, punk kids running the store. Will never shop there or do business with these clowns again! Go to Petco Waterford ask to speak to John in fish department. Absolutely disgusting how this stores are run!!!! Beware
Vincenzo Stravinski
7 reviews
Fantastic store, with world class employees who are very knowlegable about all species of fish and home aquarium setups. I rely on OSA to help me with any issues I have with my fish tanks. Love these guys!
Hello HAPPY PEOPLE
263 reviews
Nice service. Healthy fish.
Eamonn Maguire
35 reviews
The best aquarium store around
Note: Store information and services may change. Always call (401) 823-3474 to confirm current availability, hours, and services before visiting OSA Aquarium Superstores & Services - Groton CT.
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72 Plaza Court, Groton, CT 06340
February 7, 2026
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