Rock Wool Medium

[WaterWitchin]

Originally Posted by B727

@WaterWitchin @Ray
How are you working with those cubes, are you wearing gloves?
In the past I made some really bad experiences with rock wool fibers.

Ummm... I just pick them up by the handful dry. Perhaps that’s why sometimes my hands get itchy.

[Mr.Fakename]

Any updates on this subject? How are guinea-pig-plants going?

[Ray]

Originally Posted by Mr.Fakename

Any updates on this subject? How are guinea-pig-plants going?

It's hard to be definitive in just a few months, but I am not seeing any negative issues and the plants are growing nicely. I expect to go to a mix of the two for all my slippers over time; we'll see on phals.

At this point, 100% of my orchids are in inorganic media:

1) 100% LECA in S/H
2) 50% LECA/50% rock wool cubes in S/H
3) 50% LECA/50% rock wool cubes in traditional culture
4) 100% rock wool cubes in traditional culture

[WaterWitchin]

I've been slowly partially dumping and adding in some rock wool cubes as plants finish blooming, or aren't in active bloom. It appears to hold the dry line higher, especially on glass containers where I had a lower reservoir for certain orchids, then moved a higher requirement for water orchid into same pot (like switching out a phal for a phrag.) Seems to be doing the trick.

After Ray and I had the convo here about adding more rockwool, I've also done that with a few paphs and phrags. I'm nowhere near 50% each, but adding some more appears to help with the dry line on them.

Have a couple of plants that were struggling to switch to SH and I couldn't seem to keep them hydrated enough. Put some rock wool in, and they're starting to plump up and respond. Of course, just recently started doing this whole rock wool bit, so long term effect is unknown. I'm not a fan of rock wool, but if the orchids respond well and I have to water a bit less often, I love it.

[Mr.Fakename]

One more question!

I received some Grodan cubes to try S/H + rock wool; but no matter how I rinse and soak them, they release dust and small pieces that bump alkalinity up around 200 ppm.
At this point I think they lost their structural integrity and are just breaking apart.

Is that considered safe to use and the particles will go away with flushing, or is it a lost battle?

[WaterWitchin]

I think we're gonna have to rely on Bill for that one. I don't rinse or soak the cubes. And don't measure alkalinity, pH, etc.

[Ray]

I am not seeing any problems with the cubes breaking apart. Either that I have purchased here and what you’re getting over there are different, or we have to coin the term “media abuser” to you. 😇

Before I started using the product I placed some in RO water and let it soak. As I said earlier, the EC was very low, adding only 20microSiemens/cm, but the pH was slightly on the acidic side, 5.4, pretty consistent with the basalt raw material.

[Mr.Fakename]

Originally Posted by Ray

I am not seeing any problems with the cubes breaking apart. Either that I have purchased here and what you’re getting over there are different, or we have to coin the term “media abuser” to you. 😇

Before I started using the product I placed some in RO water and let it soak. As I said earlier, the EC was very low, adding only 20microSiemens/cm, but the pH was slightly on the acidic side, 5.4, pretty consistent with the basalt raw material.

Touché, I'll be needing Häagen-Dazs to recover from that blow.

The product might be different though, pH reading were around 7.9, and 7 after soaking overnight in a solution of pH 6.

I'll soak it some more and call it a day, it's going to be mixed with LECA and flushed anyway.

[camille1585]

We use Grodan and Cultilene rockwool products at work and generally soak them overnight in nutrient solution, adjusted to the pH it would be applied to the plants at (5.8). The pH does rise somewhat after the soak, on account of the residual lime left on the fibers after manufacturing. No idea about the particles though, we only use blocks and slabs.

[camille1585]

Any updates on everyones rockwool experiments? Now that spring is here and my plants are starting to grow more vigorously, I'm looking to get some Grodan cubes for my Phrags, but don't know if I'll do 100% rockwool, or mix it in a yet to be determined proportion of LECA. So I'm hoping to learn from the guinea pig plants first.