Hi there!
Sounds quite a complex design you have in mind, probably a bit time consuming to put together for people who are busy with their own electronic efforts (and headaches in my case!)...
Because you said you are fine with schematic diagrams and component symbols, and you seem to know how the individual parts/functional sections of the snake tank should look and fit together, perhaps one way of going about your project could be to break it up into each stage, then source the relevant information via manufacturers' datasheets and endless resources on their webpages. I don't know... try Texas Instruments, Fairchild, NXP, Intersil, Analog Devices, Microchip Technologies, etc., etc. - many of the component
datasheets have quite detailed application schematic diagrams, and this way you can find circuits which fulfil your objectives (some needing a little adaptation) for the snake tank and put them together to make the whole. Another option is to read up on these same companies
application notes, very useful for many things when datasheets or schematics create doubts or when troubleshooting design problems/hiccups.
Many, many web pages have schematics and explanations, some are great, others are not totally accurate, so maybe it's best to stick to (I hate to say this, it sounds unfair) reputable websites, which it can take some time to figure out which they are. Check out:
**broken link removed**
it's one example of a good site for hobbyists I trust to be accurate and reliable information.
Your project sounds a great idea, and a bit of a complex thing you want to put together, and that might take a fair amount of time, but no doubt worth the effort indeed. Maybe doing half DIY, and the other half using purchased devices might be a good idea to begin with. Circuits are (mostly) fun, especially project based ones, so I hope it goes very well for you, and for your snakes.
Best of luck!