Akerne Rain Mix?

[DesignerofBeauty]

Hi All,

I have a R/O system I use for my plants. I have mounted micro-minis and miniatures in terrariums. I also have several "regular" sized plants in pots.

I have read on this forum that Akerne's rain mix is excellent for R/O. I currently use K-Lite and I have noticed burnt root tips despite mixing at 50-75 ppm and feeding 2x per month.

Does anyone know where I can source Akeren's rain mix? I live in the US and it seems like it cannot be shipped here. It also looks like another company named "Biolan" makes a similar product.

Thanks!

[camille1585]

Is there a reason why you are specifically looking for RainMix? Rainmix is a version of MSU fertilizer, and was developed in the US at Michigan State University, hence the name. Akerne Orchids developed Rainmix based on MSU, as this fertilizer type could otherwise not be found in Europe, from my understanding. You should be able to find plenty of vendors which have MSU fertilizer on your side of the pond.

As to the tip burn you are seeing, I don't think K-lite is the problem as that is a very good fertilizer as well, and I think it is derived from MSU. What type of orchids are you using it on?

[Orchidtinkerer]

yes I agree with camille that it is unlikely to be the k-lite at 50ppm twice a month.

I mix my rain mix to about 100ppm and use it on every single watering.

RO water should not have any nutrients in it either though so have you measured the RO water before adding nutrients?

Are you sure the tips are getting burnt and not drying out instead?

[Ray]

Can you post pictures of the “burnt” root tips and describe your growing conditions?

It’s certainly not a fertilizer problem at that concentration. I apply K-Lite once every week at 100 ppm N and have never seen issues.

Rain Mix is a European copy of the MSU RO formula, and K-Lite is a derivative of it.

[DesignerofBeauty]

Originally Posted by Orchidtinkerer

yes I agree with camille that it is unlikely to be the k-lite at 50ppm twice a month.

I mix my rain mix to about 100ppm and use it on every single watering.

RO water should not have any nutrients in it either though so have you measured the RO water before adding nutrients?

Are you sure the tips are getting burnt and not drying out instead?

It's quite possible that I am letting things dry out too much. I purchased some seedling cattleyas from Lowe's that I most likely have in bark that is way too course, and it is drying out too quickly.

My system is pumping out water that is pretty pure. I just got a measurement of 6 PPM.

[DesignerofBeauty]

Originally Posted by Ray

Can you post pictures of the “burnt” root tips and describe your growing conditions?

It’s certainly not a fertilizer problem at that concentration. I apply K-Lite once every week at 100 ppm N and have never seen issues.

Rain Mix is a European copy of the MSU RO formula, and K-Lite is a derivative of it.

Okay, that makes sense. I should have done more research on the formula before posting here.

Here are some pictures. As I stated in the comment above, I'm wondering if I am letting things dry out too much.

As you can see in the third photo, there are some healthy roots and burnt/dried out roots. The healthy roots emerged and have remained green. They emerged after I stopped application of fertilizer and I suspected that they remained green because I have omitted fertilizer. However, it could be that they are only green because they are so new that they haven't had the chance to dry out yet. The burnt roots are longer in length, and perhaps had more time to grow and dry out.

[Orchidtinkerer]

They do look dried but your new roots are looking great, no sign of burns on those so maybe you could water slightly more but those new roots are a sign the plant is happy

[Ray]

I agree with Orchidtinkerer on that. Sometimes if newly-growing root tips com into contact with a very dry substrate, the tips become desiccated like that.

What is that potting medium? It's looks more like mulch than bark that has been treated for use as an orchid medium, and if that's the case, that, alone, could be the issue. Orchid bark is usually aged or steamed to extract resins. Not so with mulch, and it is those resins that might be the problem.