This is very tricky fishies, have a hard life. All mine died, my first one lasted a couple of months the rest lasted like 1 month, and I've had 3 my whole life.
Some tips
®DONT FEED THEM TO MUCH FOOD(twice or once a day, not to much, BUT NOT TO LITTLE)
®Clean the fishtank daily(Bacteria killed every single one of my fish, and overfeeding them did to)
®Put your fishtank in a high spot(AND SAFE SPOT) where it is out of reach of children under the age of 6.
Good luck.