Pumice as a layer in substrate?

[Mitsy]

While trying to disseminate some of the information I have been gleaming from all you knowledgeable folks, I came across a mention of using volcanic materials for providing minerals to plants.

Will pumice sand work for this purpose? I carve this wonderful stone, so I end up with sand and chips as a by-product. I know that ferns and terrestrial mosses grow well on this stone in the fountains and trickle towers I construct (as well as lots of blanket algae). The trickle towers really help remove nitrates on the ponds, as well as being attractive and the sound of the water falling over them is soothing.

[Ira]

It won't hurt at the very least. Probably would make a pretty good substrate, lots of minerals, good flow through it.

[kluyu]

I was browsing the posts here and noticed yours... I'm a fellow USer, although from TX. Been through Redding a good bit though... very hot and dry in the summer.

I have seen many people convert the "lava rock" or pumice into aquarium uses. It has been pointed out to me recently, however, that you may get different results on your water chemistry according to what volcanic source your rock is from.

Most of the commonly available landscaping rock should be fine. You can take the sand and chips you mention, let them sit overnight in the same water you use for your tanks. Then test that water the next day for any changes in the chemistry that may be different from your ordinary water parameters.

As you say, many people use this in their fountains and ponds, but there are many different sources and the mineral content is bound to be a real mix since it is spewed up from deep within old mother earth.