Don't think I'd bother with the Pima if you're working with tank sizes like you mentioned.
Teacup rays, that's a whole different scenario.
No such thing as a teacup, they'll still get a decent size.
If you're after rays and with the tank sizes you have i strongly suggest true Brazilian hystrix or mini marble motoro, get over to the stingray section and you'll find all the info you need
Oh wow that's cool man what size tank do you have it looks big?
Also either of the 180 gallon aquariums would pretty much just be to keep him in until he's about 18-24 inches then it's off to the pond to gain some more size. Lol
I'm still thinking I'll get one, I just want one you know, that's actually how I ended up with most of the weird stuff I have or have wanted since I was an awkward 13 year old. I feel I can house him comfortably up until about 4-5 feet what do you think?
I just really wish I could pick mine out personally to ensure its a healthy young fish but I actually found one for 190 shipped so that's a good deal and it comes with live arrival guarantee on he shipping so I'm alittle less worried about them being fragile as stated by the previous seller.
Also I know the "teacups" stingrays as I said before don't stay small forever like most people would believe,
however I'm really thinking their the freshwater stingray I'd be interested in most I just like them their one of the only ones I've ever seen in person and I could start them off in something like a 40 breeder or even a 55 gallon when pups which is cool and I could house them with just about anything that's a perk being as limited on space as is in my fish room.
I'll probably end up with all three at some point it's just which one to start with which sounds to me like growing out an assortment of monster fish that aren't quite as large as the arapaima in the tank with my Oscars is what I'll do first.
for the arapaima I'll pick one up at some point hopefully sooner then later or possibly when and if I get the rays as I could house them together in the other 180 when small until the arapaima goes in the pond along with some of the other fish I plan to get including a Aro, RTC, TSN, Pacu, Flagtail, Oscar, etc. It's just waiting and picking up these fish as I go I think the arapaima and the red tail would be the only fish to outgrow my current pond supper fast and the red tail would still take awhile based on growth charts.
I know I can get teacups for 75 a peice near me but I'll probably wait to do these once some of my other fish have gone outside or Ive rehomed them with someone who has a larger pond (If for whatever reason I don't upgrade or excavate a new pond myself) but I'm just wondering what people keep with stingrays other then Arowana or discus as I've seen a lot of these combos but few others I'm assuming the Arapaima is a lot like an aro and would work at the size I'm thinking? If I were to house these together whole young I'd love to try a pair of these with my Oscar but I feel the Oscar would produce to much waist and harass the Rays non stop. But how about possibly a pair of semi adult BPs and spotted silver dollars as well that will be in need of an upgrade by the time the arapaima outgrows this tank in 6-8 month idk now I just have to much going on thinking about fish. Haha sorry I like to think out loud on this forum so I can look back later on.