I'm sure The Fish Lady does just fine with whatever she uses. I've been in many offices which have large tanks and someone is doing a fine job of keeping those tanks looking nice - they all have similar fish to what you have in yours. As as been stated already, goldfish are considered cold water fish but they tolerate a wide range of temps. It's good to get a liquid test kit and either watch her to see or contact her to ask how she removes water.
Originally Posted by Yazikus
46 gal fw tank with black skirt tetras, neon tetras, spotted corys, green corys, 1 guppy, cherry barbs, otoclinus, snails & 4 amano shrimp - plastic & live plants
5 gal QT with green corys & 2 guppies