Lime wash for greenhouses?

Question

Ive been trying to set up the hydroponics in the green house at my high school. The problem is that most of the water evaporates so quickly that it is hard to keep the plants from drying out. the thermometer in there read 112 degrees today. when i asked my dad if he had any suggestions about what was wrong, he said that he used to have to put some sort of lime stuff on the green houses he used to work at during the summer to deflect some of the heat outwards. I live in California, it gets to about 106 degrees here in the summer and its not likely to rain till fall. What exactly is this lime stuff, and where can i get some. A recipe would be nice.

Answer 1

Get some cheap white water based latex paint and thin it down with a huge amount of water. Start with a small amount of paint in a cup to test it. Thin a bit and test a spot, thin a bit and test a spot. What you want is to thin to the point that it goes on and won't bead up, it has to stay on evenly. You want it fairly translucent with good coverage. A light, and I mean really light green tint, almost unnoticeable green tint will take out the green spectrum which is unusable to plants and that will increase the effectiveness of the covering a bit more, but not such a hugely important thing to worry about. You can apply the whole thing with a roller so it is nice and even and won't be an eye sore, or you can use a tank sprayer like for pesticide application, but be certain it is clean and not toxic. The paint will weather and wear off about the time it is no longer needed. You can do MULTIPLE coats after drying till you get the desired effect. South facing side and top are the most important, but you'll see, you only want to cover what you need, no more, as you may have to clean it off by hand later.

Answer 2

limeis  an acidic compund  which is  also a salt there is to acidic lime in the soil