You need:
-PVC Rain Gutter(cut to length of tank). Cut 1" short
-PVC Rain Gutter End Caps(2)
-Krylon Fusion for plastics(If wanting to paint, cure for 1 week(chip resistant, non-toxic)
-4 or 2 PVC End Caps 3/4"
-4 or 2 sets of nuts and bolts
-Thin wall PVC pipe(schedule 20) to fit 3/4" caps. Cut to fit.
-Optional Reflective Tape to line under side.(Found typically in Plumbing @Hardware store).
Then wrap the light around PVC pipe and secure sectioned lengths with electrical tape. If tank is longer than 36" use a left over piece of gutter and make a small brace you can wedge in between the gutter set up. All this will cost about $30-40 depending on your location. Now this is for DIY people. If you already have a hand saw and drill.