Reply To: Rock medium

[Nate]

I think it would really depend on what minerals the rocks are made of. Also it would depend on how porous the rocks are. I think the reason that clay pebbles are used is that they will absorb some of the nutrient solution, and are also supposed to be relatively pH nuetral/inert. So if you just grabbed random rocks that you found, I feel like you may run into some unforseen issues. One of the biggest ones I can think of off the top of my head aside from the nutrients just running right off, would be depending on the composition of the rocks, it may leach nutrients from your feed, or put unwanted minerals/chemicals into your feed/reservoir. Personally, I wouldn’t risk it, but it might be a fun experiment.