If you have an indoor bucket grow setup (AKA Space Bucket), you may find the need regulate the temperature of your plant independently from the heat of your lights. These instructions are for an acrylic friction-fit heat shield (no glue required) to thermally separate your lights from your plant while allowing light through.

I have included my cut files, but *buckets are not the same* so if you want a nice exact friction fit I recommend following the measurement instructions to make exactly the right size shield.

Glass heat shields are quite common in the Space Bucket community, and people report them to be 'cool to the touch'. Ekrof's tomato plant (bucket build here) has been trained to grow against the glass, as it was starting to outgrow the bucket, and the shield prevented it from being burnt.

However, the glass is expensive and hard to get cut into a circle, so this tutorial uses acrylic. The temperature of my acrylic heat shield seems stable at 28 degrees Celsius (ambient temperature is 22-23C). My light chamber is outfitted with four 32W CFL bulbs (Family Med brand) a USB fan (Stylepie Summer Fruits fan) for exhaust and extra holes for passive intake. Ekrof recommends having active intake over my set up because blowing air on the lights helps cool them down.

MATERIALS

- 12x12 inch piece of clear acrylic ($10), 3/16 to 1/4 inch thick

I used 3/16 inch thick but 1/4 is fine too. Too thin runs the risk of warping under the heat of the lights. DO NOT use the kind that people use for windows as these are likely to block UV light. You want just the plain stuff, and it doesn't matter if it's extruded or cast acrylic. I got mine from TAP Plastics from the scrap bin, and I got it on a Friday when scrap is 50% off, so it only cost me $5 for two.

TOOLS

- Laser cutter that can cut through the acrylic

Getting access to acrylic sheet and a laser cutter sounds hard, but I've lived in Toronto, New York, and San Francisco, and these things were accessible in all three cities. Ask the maker space or hackerspace that hosts the laser cutter - you will likely be required to go through some sort of safety training before being able to use it. You may also be able to convince a kind maker space member to help you cut your acrylic for you.

Toronto: Plastic from Plastic World (http://plasticworld.ca/), laser cutter at HackLab (https://hacklab.to/)

New York: Plastic from Canal Plastics (http://canalplastic.com/), laser cutter at NYC Resistor (http://www.nycresistor.com/)

San Francisco: Plastic from TAP Plastics (http://www.tapplastics.com/), laser cutter at Noisebridge (https://www.noisebridge.net//)

I haven't used the laser cutter in Toronto, but I've bought plastic at all the places listed and used the laser cutter at NYC Resistor and Noisebridge.

REFERENCES

Space bucket community for DIY grow bucket builds and tips

My grow bucket project website

My grow bucket project diary