here is a story, hope it helps.
I have kept Weather Loaches in my aquariums all my life. They are important bottom cleaners, great community fish, and are very entertaining to watch. Twelve years ago I bought a small pair for my 200 L tank and enjoyed watching them grow and clean the bottom for me. After five years they had grown to over 15 cm long and it was time to find them a bigger home. Not wanting to give them away and with no larger tank at the time, I decided to give them a try in my 1100 L pond outdoors. I live in Washington state (USA) and our winter can be quite harsh, but I figured they would be okay outdoors for the summer time and I would find them a permanent home before winter came. Well, they just loved their new home outdoors and kept the bottom spotless all summer long. By the end of summer they had grown another 3 cm, were eating out of my hands, and very fat and happy. So I decided that I would let them try the winter out there in my pond along with the Koi. I kept a close eye on them to make sure they were doing okay and they have done fine. That was seven years ago. Now they are twelve years old, live outdoors, and are over 20 cm long. I poke holes in the ice when the top freezes over in the winter and keep a small fountain going to circulate the water. I never would have thought they could survive the cold water, but they love the pond and do real well. They share the bottom with a pair of Crayfish and they all get along fine, of course the loaches are bigger. And it is true what they say about the Weather Loaches predicting the weather changes, whenever we are about to get a storm the loaches are swimming rapidly all around the pond and higher in the water column. I always know when a storm is coming just by watching them. In the summertime they laze around in the warmth of the sunbeams that reach the bottom of the pond. They are great little pets and I highly recommend them if you have a large area for them or are willing to pass them on when they get too large for your tank.