after decorating the whole house earlier this year,we had 5 x 5ltr plastic paint pots,i cleaned them out and used a saw to cut off the top rim(leaving the carrying handle intact) and drilled 5 x 8mm holes in the base and now they are in the back greenhouse with sweet red peppers sitting in them,with the opaque sides i can see whether there is water in there or not,it does take the guesswork out of it....
oh and the labels on the outside just peeled off...
