Gday mate,
They are as hard as rocks. And almost as heavy ...lol
IN FLOWER I use;
1.5Mx1.5m E&B table pots and coco; 1000W HPS + 400W MH + UVB 4ft fluro
NUTES: Cana coco, Pk13-14, Silica, Rock Juice,
Additives; H2o2, NAA, GA3, Fulvic acid.
Here are some of the research threads & Links I used...