Having tested the Mk.I habitat in the tub, it's no good. It keeps water out for the most part, but lets it rise just far enough to totally soak the dirt, even at the lowest flow level. It seems expressly designed to do this, probably because it was originally intended for use in an aquarium, and with gravel. Anyway I don't have any confidence in the ability of this thing to keep the hamster dry and safe, and I don't think it's safe to put electric lights and heating in either. As readers have urged me to put the hamster's safety above all else, I cannot in good conscience use this habitat shell.
Will I give up? Fuck no I won't. Because I lack the common sense which would otherwise restrain my ambitions, I'm going to rocket ahead and skip directly to building the Mk.II habitat:This means I'll need to carefully consider which enclosure to use as I'll need to be dead certain this time that it'll keep water out. Mainly so that this doesn't happen:That means back to square one, almost. I'll need a battery pack, a different pump, and of course a different enclosure. This is what I have my eye on:It looks ideal. Scuba dryboxes rated deeper than three feet or so tend to be pretty small. This was the largest I could find with a decent depth rating (100 feet!) with an interior volume of 7.549" x 3.606" x 3.326" (Online ruler for reference). I need to be able to fit the small video recorder (thumb sized), a small feeder, a water bottle/dish (as I've decided this will have no moon pool) and an LED light. Based on the combined sizes of these items and the enclosure as well as the small size of the breed of hamster I'll be using, I think the Otterbox 3500 will just suffice. Below is a mockup of the interior. When you click the image (and then expand it) it should appear actual size, and everything is precisely to scale relative to everything else:I plan to have the heater powered by a small USB battery pack inside the enclosure, sealed in a ziplock bag and packed under wood shavings (as some of you pointed out the hamster may be frightened and would be comforted if it could burrow). This means zero allowance for leaks, for obvious reasons. Which is why the new habitat will not have a power cable running down the umbilical, because I don't want to make more holes in the enclosure than I have to. This also means that the LED light will be self contained and battery powered as well.
Here's a list of things I still have that can be reused for the new habitat:
~USB battery pack
~kitty litter (will be packed under the shavings to absorb urine)
Here are the things I need to continue:
~Deep water aquarium pump
~Hot glue gun [edit: silicone sealant instead!]
~Portable battery pack
~USB heated gloves (for the heating element)
I can afford the hamster food, the feeder, the water bottle and wood shavings myself. The rest of it, not so much. I'm going to build this thing no matter what. But if you felt like speeding up the process by pitching in, I'd be grateful. I didn't realize how complex this project would become when I started and the setbacks have been frustrating but the concept is so great that I'm determined to make it work in the end, provided I can get my hands on the parts.
If you've got any suggestions for alternate component choices, or some kind of extra I could provide to compensate you guys for your donations (beyond the game servers I mean) let me know in the comments.