Reflectivity: Mylar vs Flat white paint

Those are about the right percentages for reflectivity. But don't sweat that aspect, keep in mind that as the light travels the distance to the walls and then back from being reflected that it is dissipating in intensity the whole way. So yes, better to reflect lost light, but an extra 10% of reflected light in a micro grow isn't going to make a huge difference in your harvest.

For what you would spend on mylar you would do even better to add more light in the first place.

 

Personally, I'd rather have a surface that can't hide moisture and create mold. I like painted walls that I can wipe down, stay dry, don't hide problems

 

You prefer any particular brand/type of paint?

 

I like gloss white or at least eggshell so I can scrub hard. I think toasty summed it up best above. The light loses energy for every foot of travel, and every time it is reflected. So the light straight from the bulb is beaming straight to the plant, but the reflected light has to travel a long ways, and be reflected 1-2 times, so whether you have painted walls or expensive foil, the light isn't much to write home to mom about.

Again toasty has the answer by suggesting investing in bigger lights rather than expensive foil, mylar, panda, etc.

 

Yeah I was asking from a moisture/mold point of view. I don't care about reflectivity, mold reduction is much more important to me.

 

Agreed. The flat paints have a porous finish, eggshell is in the middle, and gloss has the least porous surface.

 

I'm a painting contractor, so paint lies in my area of expertise. If you choose a washable paint such as a semi-gloss or eggshell, make sure to use an "interior" paint. Exterior paints have mildewcides which are harmful and your plant will absorb it in such a confined area even if it doesn't touch the painted surface. There are some high reflectivity white pants available, but you will have to go to a paint store to find them. Personally, I would stay away from spray paints since they are generally of a low quality.

 

What a great post! Thank you very much for that!

 

But...if you're going to the expense and trouble of getting a specialty paint that probably will cost $30/gallon or more, you could put up mylar. I've never had humidity/mold issues with mylar.

 

I hear you Toastyone. It's certainly possible to get moisture behind a film and have mold grow. IMHO, there's really no compelling reason to use films and foils. Good ol' interior gloss white is fast, cheap, durable, washable with (almost) no risk of mold

 

Correct me if I'm wrong but it is my understanding that flat white reflects better than gloss white and anything in the middle. The reason is that the gloss additive absorbs more light, so using flat which has no gloss additive would not have that extra absorption.

 

In reality, from a practical perspective, as the toastiest of toasties said earlier, by the time that light travels and bounces around, it is of really low energy and not worth a whole lot.

IMHO this is on of those areas where it's intuitive that something great would come from all that reflectivity, but in fact you get squat

 

There's also another paint option that just occured to me- flame retardant paint. It has nearly 100% reflectivity, but it isn't washable. The last I used of it was about 30 a gal. That was in the late 90's.

 

I'm the kind of guy that will chase down something if it offers a real improvement. In this case, I don't think there's real improvement using something other than standard interior gloss white.

Is that a ball of hash in your pic?

 

Great! You're building speakers? Am I reading that right?

 

No, I wish LOL!! It's a papaver gigantheum seed head.I grow many varieties of them for ornamental/cross breeding purposes.

 

A flatter finish on the paint is a little more reflective than the gloss, believe it or not. I'd suggest an eggshell finish if you want to make clean-ups a little easier.