Xmas Flocking on tank

#1
I've got a couple tanks out in my garage where it gets a little colder than in my house. The heaters are able to keep up alright but are on more often than not. Not much sunlight gets into the garage. Never the less, I'm using one of the tanks to grow some plants in. I put some tinfoil around three of the sides so that the light from the hood would be reflected back into the tank for absorbsion by the plants and perhaps a little heat as well. I would like to get some pieces of styrofoam that would fit tightly against the glass in order to insulate the tanks better. I have thought about painting the tanks but thought that that seemed too permanent. I know I could scrape the paint off with some trouble but didn't know if I might be using the tanks somewhere else soon.

Then it hit me. I could use some of the Christmas flocking that is around this time of year. Its white so it will reflect a majority of the light back into the tank, its kind of fluffy so it should helf insulating a little, and its easier to scrape off than regular paint would be. The only downside I see is that the tanks are currently populated and there may be some ill effects from fumes. Perhaps I'll turn off the air pumps temporarily until the air is clean again, so that fewer polutants will enter the water.

Anybody have an opinion of this Idea that they would like to share?