iPad Automatically Switching Wifi Networks

I work at a music venue, and we have about a half a dozen in-house wifi connections, all used for different tasks around the building: one controls our front-of-house mixing desk, another controls our monitor mixing desk, a third controls the mixing desk for our outdoor stage, another to control the lights etc.

None of this really matters except to illustrate that, when using our iPad, it very much matters precisely which wifi connection you are using at any given moment, depending on what task you are doing and what remote device you are operating with it.

However, the iPad seems to like to switch wifi connections automatically based on how strong a signal it is seeing... and suddenly it is on the wrong wifi connection for the task one is doing, and is thus completely useless. Apparently, this is a "feature" and not a "giant fucking bug."

How do I put my iPad on a specific wifi network and have it STAY ON THAT WIFI NETWORK until I decide otherwise, without forgetting all the other wifi networks in the building?

This is very very frustrating.