dojo loach

More would be better.

Make sure you have a secure lid and block any openings on said lid.

They get to a fairly big size, like eatn size so give them a big tank.

upgrading is not really a problem. I am going to start them off in my 46g and when they get big enough I have several larger options. I really just want two or three of them. Are they comfortable in a pair or trio?

They are OK in small numbers. They are not usually aggressive toward each other or the other fish. They tend to be more active, more visible in larger groups.
A 46 (is this a 46 bowfront?) is a good start, but yes, a longer tank, more floor space is better.

thanks the tank is a bowfront, I am not sure if there a non bow 46g. I keep mostly large fish. Right now I am putting together two community tanks which I haven't done in years. One at my home a 90g discus tank and another at the office. I want the office tank to be nice, but I am also going to use it as a grow out tank for fish I want.

I did not think there was a non-bowfront 46 gallon, either, but just checking.

That tank is not well layed out for bottom dwelling fish. It is tall, but only 3' long. Pretty good for schools of small fish, not for larger fish. They cannot get swimming really well before they have to stop and turn around. The sooner you can move them into a longer tank the better. They need floor space.

Perhaps googling has already shown you this, but this site in general is a good resource for loaches:

http://www.loaches.com/articles/weather-report