Question on S/H media

[IdahoOrchid]

I have two plants that I recently switched to S/H. The only media I could find locally was lava rock so that's what they're in and they are doing great.

It occurs to me that the roots might like being surrounded by something a little smoother than the fairly rough lava. The first thing that comes to mind is round river rock, the kind you can find in the landscaping sections of the boxstores and Lowe's.

Does anyone see a problem with smooth river rock in S/H? I know they won't be as porous as lava and clay pellets, but is high porosity a necessity? Maybe I could just put the holes an inch or so higher to keep the water closer to the roots....?

If you want to know even MORE about s/h culture just go to the forum on Semi Hydro and read past posts and post new questions there. We won't bite, really!!!!

[agolley]

Okay great. Thanks guys I appreciate the help and will try to post some of what I have in bloom at this time.
Andy

[Jmoney]

river rock won't wick at all, and lava rock wicks minimally. the sharp surfaces won't be a problem for orchid roots as long as they are anchored well, but if you're looking to grow s/h-style, lava rock won't work. you need the fired ceramic pellets...I use prime agra because it wicks great and has irregular shapes so it locks well in the pot, but you can use the rounder hydroton, which will wick decently although it won't pack in as well due to the shape..hydroton is also quite buoyant, which is annoying when you water (primeagra doesn't float nearly as much).

if you use lava rock, which is a perfectly good medium if you like fast draining mixes, I would suggest not doing it s/h style. I know people in hot humid climates (i.e. hawaii) have used lava with good results, they just water all the time. it will also accumulate salts so you'd have to flush regularly with pure water.

[GiovannaD]

I know what you mean about the annoying buoyancy...I personally use a big bowl and a ladle to water the plants without having the pellets pop up like CocoPops when water reaches all the way to the rim. However I find that the plants don't mind the shuffled media and it prohibits algae from growing.