Alright so I can't find rockwool cubes or hydroton or net pots. I don't want to risk buying it online. So can I use a never before used standard yellow sponge instead of the rockwool and hydroton balls? like make a big cube for where to put the seedling and then cut up up smaller cubes to surround the big cube. Also what or where other than home depot can I get a net or make a net pot? There's no hydro stores near me.