Volcanic Red Lava Rock as S/H media

[shadytrake]

No Rodrigo. The ones at the top were in lava rock. None are in lava rock now.

All of them are now in hydroton/arkolite mix.

[RJSquirrel]

the book "understanding orchids...." by william cullina states that lava rock is fine to use for orchids but NOT if you have high amounts of dissolved solids in your water as the rock tends to absorb a lot of the salts..so as long as you rinse wash and repeat on a regular basis lava rock is not a problem.

But what I'm really seeing is the people that use it as a common media are the ones where its readily available and comes right out of the mouth of a volcano..I think using lava rock is more of an economical substrate used by growers in volcanic areas.

[Brotherly Monkey]

Originally Posted by RJSquirrel

the book "understanding orchids...." by william cullina states that lava rock is fine to use for orchids but NOT if you have high amounts of dissolved solids in your water as the rock tends to absorb a lot of the salts..so as long as you rinse wash and repeat on a regular basis lava rock is not a problem.

But what I'm really seeing is the people that use it as a common media are the ones where its readily available and comes right out of the mouth of a volcano..I think using lava rock is more of an economical substrate used by growers in volcanic areas.

I use the stuff from Lowes and many of my orchids do great in it. Though I can see why seedlings wouldn't do well in the stuff, since the pieces are so large

PS I don't think there would be much difference is how hydroton and lava rock would would behave in regards to salt build up. They're pretty similar in how they act as a media, with the main differences, from my experience, resting around size uniformity and texture

[Ray]

Originally Posted by Brotherly Monkey

PS I don't think there would be much difference is how hydroton and lava rock would would behave in regards to salt build up. They're pretty similar in how they act as a media, with the main differences, from my experience, resting around size uniformity and texture

Sorry Bro, I gotta disagree. Each of product used as a potting medium component has its own absorption/release hysteresis, and they vary all over the map. The greater the hysteresis - i.e., the slower the release compared to the absorption - the faster the buildup.

It mostly revolves around pore size: small pores tend to get totally filled with solutions thanks to surface tension, while bigger pores tend to be wetted mostly on their surface, and in irregular nooks and crannies. Liquid in a small, totally-filled pore stays as a liquid and can be passed back out easily. Liquid in a larger "coated" pore can dry out and become solid precipitate that is much slower at redissolving and release. LECAs tend to have smaller pores than does lava rock overall, and some brands have a more uniform dispersion of very fine porosity than others.

[Brotherly Monkey]

Originally Posted by Ray

Sorry Bro, I gotta disagree. Each of product used as a potting medium component has its own absorption/release hysteresis, and they vary all over the map. The greater the hysteresis - i.e., the slower the release compared to the absorption - the faster the buildup.

No reason to be sorry. After all, the entire point of participating here is to discuss these things.

[jmce96]

i live in mexico, and laste year i went to a Dendrobium phal. farm that sells cut flowers for restaurants and hotels, all their dendrobiums are growing in plastic pots with holes and lava rock and they are very healthy and get huge!, they fertilize their plants once a month and mist them daily.

---------- Post added at 01:12 PM ---------- Previous post was at 01:12 PM ----------

i live in mexico, and last year i went to a Dendrobium phal. farm that sells cut flowers for restaurants and hotels, all their dendrobiums are growing in plastic pots with holes and lava rock and they are very healthy and get huge!, they fertilize their plants once a month and mist them daily.