Now you need to make the top of the bubbler, which means you make a template from your net pot, trace the pattern onto the lid of the Rubbermaid container, and cut the holes using either a utility knife or jigsaw.

First, take your net pot and trace a pattern on a piece of scrap cardboard, then carefully cut it out using a pair of scissors or a utility knife. Once it is cut out place your net pot into the hole in the cardboard and check to make sure it is a good fit. It should fit snug so that it will keep light out of your reservoir.

When you are satisfied with your template, lay out the patterns and trace them on the lid with a Sharpie or permanent marker.

This is where you have to be careful. Ideally you have, or can borrow a jigsaw. It will make it much easier and safer to cut the holes for your net pots. If not then you will need to use a utility knife which can be dangerously sharp and it's easy to slip and hurt yourself.

If you have a jigsaw drill a small pilot hole and insert your saw blade in this hole, then cut out along the the pattern you drew with your Sharpie. For those using a utility knife you will want to have a piece of wood or thick cardboard underneath the lid when cutting it. Slowly insert the blade into the lid along the Sharpie line, and while holding the utility knife at a slight angle slowly move the knife along the pattern. Repeat until all net pot holes are cut out of the top.

Last you will need to drill two 1/4" holes in the top of the lid so that the air lines can be inserted into the reservoir.