Add 2 or 3 more weather loaches and you'll have happier fish. They are very social, and when in a group (with a good aquarium setup) they tend to be very active and playful. Like most other loaches, they require clean water, enough space to swim around (a 40 gallon tank is usually considered a good minimum for weather loaches, though tank area is more important than volume), plenty of places to hide, and lots of friends of their own kind. Having a few other fish (often referred to as dither fish) swimming around in the tank with your loaches is a good idea also, as the loaches actually count on seeing other kinds of fish swimming around to know when it is safe to come out.
I hope this helps.