Other than cutting the platform with scissors or snips, the only other fabrication is to poke holes in both the platform and the deli container (soil wick). I used a metal skewer heated on the stove. Of course, you could also use a Dremel rotary tool if you have one.
This method isn't just for buckets. It is an easy, low-cost way to convert all of your planters to sub-irrigation. You can even use it in a clay pot. To make it watertight, spray (or brush) the inside with tree wound paint and plug the drain hole with caulking.
The platform was cut from a vinyl floor tile. It rests on a 16 oz plastic deli container, which creates a soil wick. The fill tube is 1" (3/4" i.d.) vinyl tubing (it could be PVC pipe).
Although I made it from purchased materials, this planter could be made from all recycled materials.
Purchased items: (Lowe's)
12" x 12" vinyl floor tile .45
1" vinyl tubing 1.80
Sub-total – insert 2.25
5 gallon utility bucket $2.78
The same construction can also be used to make sub-irrigated tote box planters, a post with photos to follow.