What you need to know

There are several things you need to know when keeping rays.  If you can not provide these things ask yourself, "Is this the right pet for me?"  The following is not meant to scare you off, but for you to think about before you throw lots of money into the hobby.
 

Stingrays need a big tank.  Not all species, but most of them do.  A pair of 8" rays need at least an 60 gallon tank to start.  But you have to know, you will need a bigger tank in the future.  Height in a ray tank is less important than the width, 24" being the minimum for the smaller species.  For the larger ones, 30" is a minimum width, and the really big ones (Potamotrygon Menchacai) require at least 50" in width.  With rays the saying goes, "the bigger the better".  (But honey, you told me it was how you use it that counts...)  There are people in this world who think even this, isn't big enough and build tanks with a width of 85" or more.  But then you must have the space and money.
 

Watch out.

Rays are poisonous.  They have at the end of their tails a venomous stinger.  The rays shed this stinger every 3 to 6 months.  If you come in contact with this stinger due to ignorance or accidentally, (or maybe both), go to the doctor or hospital immediately. You will require medical attention.  The rays will never deliberately sting you as the stinger is used for self-defense.  But when cleaning the tank always keep in mind the location of the rays for your own safety.  I saw once, one of my Leopoldi's shed a stinger.  I picked it up with my bare hands, and the rest of the evening I had a numb sensation in my forearm.  It felt like a current of electricity had gone through my arm.  I enjoyed that feeling for the rest of the evening.
 

Aside from a big tank, a very good filter is also very important.  I recommend a three chamber biological filter.  A ray eats a lot so you need good filtration.  Remember nitrates are deadly to stingrays.

A ray has a big appetite which can be expensive.  I don't want to exaggerate but look at the food section of this site, and you can imagine that this food is more expensive than pellet food.

I don't wish to exaggerate but these are things you should know before getting started with rays.  the stingray tank is just as expensive as running a big cichlid tank (rays are generally more expensive than cichlids to purchase).  But more affordable than a saltwater tank.

At last, I want to tell you that there is nothing more beautiful, more graceful than a freshwater stingray.  I know you will enjoy these marvelous fish.