Hey guys,
This is my first time posting on this site so I'll try and keep it to the point.
I'm creating a hydrogen cannon for a engineering project at my university and figured I'd get some help with my electrode configuration.

The design is a simple Stainless steel parallel plate set up. However, I am worried that the different sizes of the plates within the acrylic tube will mess things up. (24 plates in total) The plates are all 1' tall and they vary from 7" to 2' in width.
So there's a whole heck of a lot of surface area here.

The goal is to run this thing for pretty much 8 hours straight for one day with a few minute breaks once in a while. So just raw hydrogen production.

Im looking for advice such as:
-do i need to worry about heat for just one day?
-what plate set-up do i use (+-+-+-+-+ or nuetrals) for a good balance of heat reduction and raw HHO production?
-what is the best way to connect the plates to a power source for whichever plate set-up is used?
-is 1/4" spacing too much for a basic distilled water and salt electrolyte solution?

Also, since these are so large, I need a way to maintain the seperation of the plates. I was thinking a 7" (ID of tube is 7.5") threaded nylon rod through the center of the plates at the top and bottom with 1/4" wide nylon spacers between each plate.

Thanks in advance for the assistance. Any help would be greatly appreciated.