hydroton pebbles, how much is too much?

Hey peeps what's doin? Between my last DWC grow and this one I decided to do a small experiment involving hydroton pebbles and how much I used. In my June2010 DWC grow, I used 5"net pots, with 2" rockwool cubes, so about 8 layers of hydroton pebbles, rockwool cube, then the netpot was filled with hydroton pebbles so maybe 2 layers on top and heaps down the sides...I did find that the side roots found it hard to get through the hydroton without constant top feeding (which ive noticed is an issue alot of people seem to have on here, realise it or not)

This grow, again I've used 5" netpots but this time i went 4"rockwool cubes, which only meant 2 layers of hydroton on the bottom, had barely enough room to get a layer down the sides, and one layer on top. The netpots on my last grow got shredded open, Im expecting these ones to get absolutely destroyed!
I can comfortably say that larger rockwool cube/larger jiffy pot (whichever is preferable) will encourage alot more root growth from top to bottom of the netpot, which Im sure makes for a happier plant. Hope this helps anyone who read it!

5" Net Pot


3" Net cup


both 1" rockwool cube

Nice pics Weedler +rep

hell yeh nice root porn! is that pic of the 3" netpot only 3/4 way up?? looks stacked up pretty hard! repd!

2" rockwool cube


both pots were emptied of the pebbles when the shots were taken. the plant to the left, all the roots grew straight through the bottom, didnt even effect the netpot really...the one to right, the cube placed lower in the pot admitingly but as you can see again they've grown straight through the bottom and the main taproots only split the sides on the way down.

4" rockwool cubes.

It's only veg and still too early to make a "proper" end result comparison, but yeh as you can see on both plants roots are just shooting like crazy out of the side


it's not the clearest i'll take some more shots tonight at lights on, but you can see how much hydroton ive got in there compared to rockwool. really ive only got it down the bottom directly off the water level so the rockwool isnt constantly soaked(not sure if this matters though?) and down the sides to keep it stable in there