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In this post, I walk you through what decisions I had to make when deciding how (or if) to paint my farm. After reading this you’ll know what to put on your walls for any indoor grow room, hydroponics or not.
This is part of my series on building my own vertical farm proof of concept. For the introductory article, start here.
The surface on the walls are important: proper reflection can increase lighting up to 30%. Perhaps more importantly, the reflected light helps even out your light coverage and prevent dark spots beyond the canopy. This happens because is able to bounce off the reflective covering of the walls and ceiling and come at the plants from many different angles. Thinking this through will make your grow lights seem brighter and more powerful without actually increasing the amount of electricity you use.
Playing into that is situating your plants and lights close enough to the reflective surface for that to make a difference, but since I’ll be setting my pallet racks and plants against the walls, I’m all set.
Now, I’m no Bob Ross, but I thought about painting quite a bit. I had decided early on against anything else for a few reasons. I’ve grown in rooms before that use something like hammered aluminum, the material on the inside of grow tents for example, to make the lights shine as brightly as possible, but that didn’t seem like it would be as neat or as forgiving (for both maintenance and installation*) as a few coats of paint. It’s also definitely more expensive. It is actually more reflective, but I’m eager to get going on my project and it would have been one more thing to find a good source for. Paint I knew I could just get at the hardware store.
The best type of paint to use is a white, latex based, antimicrobial, scrubbable paint with the flattest finish possible.
Let’s break that down:
- I wanted white paint because it disperses heat without trapping it close to my plants, meaning there is less worry about venting or temperature control
- I wanted latex-based paint because it helps waterproof my drywall**
- I wanted antimicrobial paint to control for mildew or mold growth in case my humidity gets out of whack. I’m not super worried about water spillage since I won’t be top watering, but this, combined with the caulking I did around the space where the wall meets the floor should keep my insulation nice and safe
- I wanted scrubbable paint so I don’t have to worry about paint coming off during cleaning
- I wanted a flat finish because it actually reflects more light than a glossy one (85% reflectivity – though I don’t entirely understand that metric)
All in all, while not the absolute highest “lumen saving” option, white paint is the best. It’s affordable, easy to install and use, improves the durability of the space, and does a fantastic job. It made the choice easy for me and only cost around $50 for 2 coats of around 480 sq feet of coverage.
*improperly installed surfaces like this can create air pockets, leading to hot spots, reduced reflection, or moisture buildup.
**lesson learned on new drywall for me- it sucks up a lot of paint. I went through two cans painting the walls and ceiling and I could probably do another coat.