Thank you everyone for your positive remarks; I appreciate them.
Is the plastic drawer the one in the middle with the HOB filter? What's the casing you're speaking of?
I assume these are some of those plastic storage chests, but I was wondering if by casing you meant the frame or something you improvised for sturdiness.
Did you have any concern about the plastics and what they're treated with? I saw mention of there being a chemical they use to keep them flexible that may be harmful to fish.
You had some bulkheads there, what kind of central system were you running?
Thanks for sharing the pics and info, as someone said it's inspiring to others. I know it's giving me some motivation.
Yes, the middle photo above, the cantilevered "tank" is the plastic drawer.
By "casing" I meant the part that the drawer slides into. In the middle picture, you see this, whereas it's missing in the wagon picture. The drawers aren't structural enough to hold the water without the casing, but by using the casing, you get the added structure, plus, in my case, I used sheet styro to line the space between the drawer and casing for insulation and energy efficiency. BTW - the "roof" of the casing has been sawn out.
I did learn to be very careful selecting plastic goods. Cheap brands use cheap polymers or thin walls that will crack or shatter sometimes. So I went with expensive brands and looked for designs with reinforced lines, as water exerts a lot of force on a wall and floor. I personally don't worry about plasticizers in a top brand product. LDPE, HDPE (low or high density polyethylene), polypropylene, and polycarbonate are the plastics to look for. LDPE, HDPE, and polypropylene are milky clear. Polycarbonate is clear. If a plastic container is glass clear, fairly cheap, and doesn't claim on the label to be made of polycarbonate, steer clear, as those non-polycarbonate clear resins (often acrylic) are prone to shatter under stress.
My systems use central water in, central drain out plan. There are many ways to do this. To spoon feed the details wouldn't be sporting or help you exercise your lateral thinking, and it depends on your other infrastructure and budget too, anyway.
I will add that all my systems are through GFCI power. I have other safety nets, too, that come into play when one starts to get a number of tanks set up. (sump pumps, water alarms, power back-ups, etc.)