I like the extremely reflective, extremely tough paint used to put lines on highways.It also seals.
Is anyone using paint actually bleaching their walls between runs? If not, have you had any problems after 18-24 months?
We like FRP (Fiber Reinforced Plastic) for wall treatment. Reflective enough, affordable and easy to sterilize. Stainless cladding is nice also, but more costly.
We use to bleach a plugging room and coolers in our cut flower operation.
The trick is two items one no plants in the area using 10% bleach solutions. Ventilation after bleaching is a must for plants and people. Als, remember diluted bleach has a very short shelf life, in the food industry they say 20 minutes. So make small batches
There are lots of alternatives to chlorine based bleaching. That are more friendly to the use and plants. Qualin based salts can be used in swamp coolers and other applications, Green Shield . The active ingredient is Quaternary Amines. We used it for years in our evaporative coolers.
The active ingredient in things like oxyclean, is just a dried form of H2O2 aka hydrogen peroxide, Sodium Percarbonate. You can by it in bulk as a pure form. It is used extensively in European operations instead of chlorine bleach. The Europeans have a thing about chlorine and people.
I have used old fashioned white was as a paint in clean rooms. If you change the formula to bordeaux mixture you get an outstanding bioside. Check local laws.
Amorphous copper hydride, can be added to paint or white wash. We used it for slug control on the side of Sweetpea benches.
To us at Oregon Coast Farms the reason to use reflective mylar has to do with spectral vs. diffuse reflection. If your light source is above the plants, it would not seem logical to reflect this light back over the tops of the plants. If you look at a large grow room, the edges of the room will be low in flux level because there are no adjacent lights to make the edges uniform to the interior of the room. If you do it right, a spectral reflector will overcome this condition.