Growstone

Interestingly, I had bought a bag of Growstone maybe 6 months ago for potentially adding some to my orchid mix, but reluctant to do so because of the ph concern. I finally took a few of the Growstones, put them in small amount of water overnight and check the ph in the morning: PH 6 - so mildly acidic.

 

What was the pH of the water beforehand? Also keep in mind that the fresh stuff has had its surface passivated through an acid wash, but that's quite temporary.

I have heard of success if it is mixed, roughly 50/50 with sphagnum, so the acidity of the moss counteracts the basicity of the glass.

 

water was 6.5 - but I see your point - I may just give it a try mixed with sphagnum moss for one or two orchids. thanks for the information

 

I use Growstone mixed with Orchiata and LECA to grow Laelia Rupicolous orchids. They grow very well in this mix. The Growstone is small and mixes well with the smaller LECA and Orchiata sizes. The LECA provides weight, the Orchiata provides a little moisture retention, and the Growstone provides stability.