Very cool. The tub comes with a built in drainage..... I'll have to keep this in mind for a future bin.

Yes it comes with a built in drain, however a couple tips, make sure the tub is slanted to that side so the water can flow that way. Also put some screen, landscape fabric over the drain or it will get clogged, I know this because mine did. Was really gross as I found it was full of water so I had to fork out the wet bedding/food/worms into a little pool, then bucketed out the water which I used to water a few plants with, then cleaned out the drain and created a screen. We don't seem to have a water issue anymore.
Sandy

Hi! I too am composting in an old bathtub, which sits behind my shed, in the shade. I taped a mylar tarp to an old window blind as wide as the tub is long, and attached it to the shed, above the tub. It rolls up out of the way, and unrolls over the tub at about a 45 degree angle, so there is plenty of air movement, but no direct sun hitting the tub. The blind sort of "self hooks" over the lip of the tub, and water from the roof of the shed just rolls off down the tarp, bypassing the tub. The tub is a GREAT set-up. I put about 3 inches of stone in the bottom of the tub, with a larger stone over the drain--not sealing it, just to keep everything in the tub, and then bedding of shredded newspaper and leaves about 50-50. I have a small container under the drain, and always have leachate, which I usually throw back into the tub. MY biggest problem is the super efficiency of what was originally about a pound of worms--they have far surpassed the famed reproduction rates of rabbits! I am now feeding 10-12 lbs of stuff per week, generally several lbs. every other day. I had to completely change out the bedding in less than 3 months of operation. I had worms all winter, and even though it has been very warm here this last month, the worms seem not to have noticed. I think temperature control is less of an issue in a larger bed. Also moisture control--if it's a bit dry, I just douse with water--everyworm has a bath and the excess moisture drains right off. I do feed frozen food, although this winter I won't. Prior to the tub, I maintained a 20-gallon rubbermaid bin for 2 years or so; this larger bed is just SO much easier to care for--NONE of my fears concerning adequate air flow, moisture levels & tub environment materialized.

OOPS! I forgot to mention, I did line the stone layer in the bottom of my bathtub with landscapers cloth (the water permeable kind), with excess cloth draped up and over the edges of the tub. I wrap the cloth tails over the bed, unwrapping to add food, and rewrapping. The worms seem to love it--I often find them directly under the cloth, gnawing away at the food underneath. Perhaps because the cloth is so dark? Makes it easier to change out the bedding without disturbing the stone layer, too.