I went Atlantic Tropical Aquarium for pricing on tank and saw their fish selection. Poor service and will try to sell you things you don't need. This place is a hole in the wall sort of place and the guys there are shady.
If you want a excellent service and best acrylic tank price then go top Jim's Exotic Fish. He will offer FREE delivery service on tanks if you're within a 10mile radius. Excellent servic, excellent price on fish and equipments, wide selection of fish and salt.
Jim's Exotic Fish
630 North Sepulveda Boulevard
El Segundo, CA 90245
310-322-FISH (3474)
Here is a list of places I've been to and have had good experience with. I left Sunset Aquarium out in El Monte since that was already mentioned in a previous post.
Super Pets
9403 Las Tunas Dr
Temple City, CA
626-237-0715
Super Pets is kind of like Petsmart but wider selection of fish and equipments. Excellent price and friendly service.
CK Aquarium
431 S San Gabriel Blvd
San Gabriel, CA
CK Aquarium sells a lot of off brands China made equipments. I wouldn't recommend buy off brand China made stuffs unless you have confidence in there product. Good place to buy aquarium background, floss, bio cermic rings, fish food, and small tanks under 20gallons. For example, I paid $2 a ft for 24 width background. Petsmart would sell the same for $7 a foot. They have a decent selection of arros, plecos, flowerhorns.
Jebo Aquarium Warehouse
513 Monterey Pass Rd.
Monterey Park, CA
626-289-8326 Cell: 626-226-9038
http://www.jeboaquarium.com
This place is an authorized Jebo seller. They only have Jebo stuffs and carry a complete line of Jebo products. This is a warehouse type of setting and they do not sell fish. Offer great prices on Jebo products. Ask for Chris/Store Clerk was very helpful.
Lee's Aquarium
319 E Garvey Ave
Monterey Park, CA
626-571-4982
Small place but has really good fish selection. He get dats, arapiagma, rays, sturgeon, bichirs, atf, red belly. Price is not cheap but fair.