Back when I used Coliseums, the concrete wire was 1 foot from the center, so a 2 foot diameter wire-cylinder.
General rule of thumb, 1 ft of plant volume, screen, 1 foot air, cool tube with bulb. After you do that, your main problem is getting higher plant numbers for an even growing canopy, and sufficient root zone size.
General rule of thumb, 1 ft of plant volume, screen, 1 foot air, cool tube with bulb. After you do that, your main problem is getting higher plant numbers for an even growing canopy, and sufficient root zone size.