Well now I know why you need sand! And growing in heat like that at 4000 feet! EEK! Seems you have adapted some growing techniques to your own personal niche, and it works well for you. Man, 90 to 95 degrees is warm for soil temps with live plants in it, but oven hot!?!?!?!?!? HOLY CROW!!!!!! THAT I have not experienced before. I hope to never have to!!!!!! Good job, Steven!
Write a book. Call it, "CP at 4000 feet, and how to grow them." Won't sell many, but the growing techniques for your elevation should be worth their weight in GOLD!
Around these parts, 110 degrees F. is not uncommon. Soil temps rarely reach the upper 80's to LOW 90's. Using white tubs for growing does help reflect heat. Plus, being so near the Pacific Ocean has some advantages. Like light sea breezes blowing through occasionally, humidity rarely below 15%. Admire your tenacity, XSCD!!!! Keep it UP!!!!!!!!!