In the last post I laid out some possible future paths this project could take. To go any bigger/more ambitious will take more money than I have.
On the other hand I seem to have arrived at an essentially perfect design with Hambase Alpha. It's been flawlessly reliable, safe, with exactly enough space for all the necessities and some unnecessary comforts. It's balanced neatly between the interior volume/elbow room needs of the hamsters, and the limits on how much weight is practical/comfortable to pick up and move around out of the water.
There are very minor improvements I could make in a revised version: I've found a single power cable that can supply both heating pads, rather than using two. And there's an unnecessary exhaust port in the side which I discovered only created a second unsightly bubble trail; Bleeding air through the seal is totally sufficient, any excess just intensifies the bubble trail. So in a few small ways it can be simplified, for less construction effort, fewer hull penetrations and a single power cord instead of two. But the enclosure, weights, ballast pods, heaters, everything else is just about ideal.
I wonder what I am accomplishing, then, by keeping it underwater. It could stay down there for years. For the entire lifespan of the hamsters. I have total confidence in the design. I could go bigger, with more rooms, but they likely wouldn't use them, it would make it much heavier, I'd still have to surface it for cleaning, etc. The size of habitat I'd need if I were going to leave it permanently underwater is cost prohibitive. So I'm at this point of stalemate, design wise, where I've made it as good as possible within given cost and weight constraints.
In light of this I've decided to start keeping the hamsters on the surface in a much larger enclosure for extended periods. I've proven the design concepts I wanted to. There's no practical need for them to stay down there all the time until I can afford to build something larger that pushes the envelope in some way. What I'd really like to build is the large acrylic dome habitat which I can partially surface inside of. That is, I believe, the size necessary for permanent emplacement, as it allows me to get inside of it myself to do things like scooping/replacing litter, resupplying food, etc. without the risks inherent in any sort of motorized docking ring. The problem is, this final and largest of habitats would cost a great deal of money. It would have legitimate scientific value, permitting the study of multigenerational effects on mammals of living out their entire lives, reproducing, growing up, everything, while relatively deep underwater (25 feet) and in a pressurized environment. But to make this happen I'd need funding, and I have a hard time imagining anyone with a few grand to throw away wanting to invest in a project like this.
So until I have cash to blow on a larger habitat, the hamsters will be spending only some of their time underwater. Probably one week in, one week out, alternating. And the Ustream will be offline until my PC is fixed, as I am down to my laptop now, which is what I was using for the stream.
P.S. Although the dome habitat is what's required to do any actual worthwhile studies of underwater lifecycles, one thing I have demonstrated with the project so far and that I'm pleased with is how simple the principles involved in shallow water ambient pressure habitats are, and by extension, how achievable low-tech underwater living is for human beings, should we ever want to do such a thing.
Let me know what you think in the comments.