Akerne rain mix + CaNO3 to get low K result?

Slippertalk Orchid Forum

Help Support Slippertalk Orchid Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
A balanced 16-16-16 fertilizer at 1/4 strength alternated with a cal mag 15 - 5 - 15 jacks brand at 1/4 strength works for me, I'm not saying that to argue, just saying thats what works for me
 
I guess this discussion shows different philosophies in thought processes, more than anything else. Personally, just because "others have done so" doesn't bestow a huge amount of credibility to a practice, and usually guides me to look into it as a challenge. "It's always been done that way", by itself, does not mean it's right.

Also, we cannot forget that correlation does not necessarily mean causality. I find the statement "the best growers with the best results and all the awards don't do it" - an implication that it's the use of higher potassium level that leads to awards - to be absurd. It's just as likely that those growers - large-scale, commercial growers, for the most part - get more awards because they have much larger populations to select from, tend to show their plants more in order to enhance their commercial value, and use a "historical" fertilizer because they're readily available and "they work", taking a variable out of their cultural concerns. "What the plants get" does not mean it's "what the plants require".

If you search back a few years, the orchid grower at the Huntington Botanical Gardens showed off several of their FCC's, stating they were fed only calcium nitrate.

I think that there simply hasn't been enough research into the nutritional demands of individual orchids for anyone - including you and me - to say for certain what formula is "perfect" for what plants, and it can vary all over the map. There is some data in Marschner showing uptake of K by maize to be nearly 10x that of onions, and that by tomatoes is 350% of maize. Orchids? Unknown.

I think there is another thought process being demonstrated here: I will not state that the use of a low-K fertilizer is "the best" or even better than the use of a high-K formula. Mimicking Troy's comment, it seems to work fine for me. Others, on the other hand, seem to be adamant that it's a terrible idea - with no experiential basis.
 
Last edited:
I agree with you Ray. I use rain mix at half rate and get great results. Could I do better? Maybe but I'm happy where I am.
If you talk to the Fischers at OL you'll realise that the pro's take this research and understanding to a whole other level but as they've spent time and money on this and it is their profession it is proprietary and mainly confidential information.
They may present information in their talks but you don't tend to see it written down.
I am sure it is the same for other orchid pro's.
David
 
I'm using Ray's protocol of K-Lite, Kelp Max and Inocucor and the growth I have seen in just the past few months has been nothing short of incredible. That being said I have made several other changes in my culture including a switch from organic media to inorganic and the use of RO water instead of tap. Maybe the bug juice is magic, maybe my plants are doing better because I'm not afraid to water several times weekly now in the new mix, maybe the truth is somewhere in the middle. All I can say for sure is that I am very happy with what I am seeing.
 
I agree whole-heartedly with Stone's assessment that frequent flushing is critical:
Also vitally important is to get a feel for what is going on in the pot. Nutrients usually build up over time regardless of how low the concentration but not just that, certain fungi build up as well if the pot is not full of roots, these fungi kill roots. Not directly but probably some exudation from them. It's what is normally referred to as stale mix. To prevent this you need to leach by flushing out with a strong and sustained stream of water 2 or 3 times in one day one hour apart. (if you're not sure that the pot has been flushed well it probably hasn't) This seems to wash out all the crap including salt build up which inhibits healthy roots.
Water is truly the driving force for plant growth; fertilizer is far less important, but residues in the pot can inhibit plant growth. And while I agree there will always be buildup in all media, the use of very low fertilizer concentrations, while not only closer to what the plants see in nature, will slow the accumulation. Keeping the medium moist also helps prevent precipitation.

I don't think it's the case (and I have hundreds of customers who agree with me), but for all I know, the use of K-Lite - by itself - might be a merely "subsistence diet" for the plants, but when the KelpMax and Garden Solution are added to the regimen, they may provide enough supplementation to truly satisfy the plants without overwhelming them with ions.

In addition to the stimulating hormones and other plant growth regulators, KelpMax contains a small amount of N-P-K nutrients and trace elements, plus proteins, carbohydrates, amino acids and vitamins that plants can manufacture themselves, but can be absorbed as well. Some of those are also consumed by the beneficial bacteria in the Concentric Ag product, allowing their populations to grow.

Here's an excerpt that I think explains what the "critters" in the stuff do:

The beneficial bacteria primarily protect plants by competing with pathogenic bacteria, and exuding antibiotics into the rhizosphere that kill pathogens and prevent them from harming the plant. Additionally, as the bacteria grow and multiply, they secrete amino acids and plant growth stimulating hormones.

Beneficial fungi also compete with others and secrete antibiotics, but have the additional benefit of parasitizing them, as well. They generally do that through a mechanism of cell wall degradation, which not only kills the pathogens, but converts them into nutrients that can be taken up by the plant. Besides those, the colonization of the roots by the microorganisms offers additional, significant benefits.

As the fungi grow, they extend hyphae throughout the root zone and potting medium, and mycorrhizae directly into the plants' root cells. To fungi, hyphae are analogous to roots on a plant, and become an extensive network capable of absorbing water and nutrients. The mycorrhizae are the pathway that the fungi use to pump nutrients into the plant in exchange for sugars. As plants' roots can only absorb nutrients that are very close to them, the hyphae network plays the significant role of "extending the reach" of the roots, enabling uptake from a larger area of the host tree’s surface (or for us, in the pot). The fungal hyphae absorb water and nutrients, transfers them to the fungi, who in turn, transfer them via their mycorrhizae directly into plants' root cells. Fungal hyphae are apparently particularly good at absorbing and transferring phosphorus, copper, manganese, and zinc, helping complete the plants’ nutrient needs. Additionally, fungal hyphae can absorb and trap excessive levels of dissolved solids, precluding them from stressing the plants.
 
Yes plants need P for root production but they need it just as much for the whole plant. The old claims that P is for root growth is not true. In other words, giving more P than is necessary for the normal growth of a plant will NOT increase root growth. It has been tested in trials a number of times. But yes I agree that any standard fertilizer off the shelf of your favourite hardware store will give you the basic NPK that you need. 1-0.3-1 or 10-3-10 is about right..Yes plants need P for root production but they need it just as much for the whole plant. The old claims that P is for root growth is not true. In other words, giving more P than is necessary for the normal growth of a plant will NOT increase root growth. It has been tested in trials a number of times. But yes I agree that any standard fertilizer off the shelf of your favourite hardware store will give you the basic NPK that you need. 1-0.3-1 or 10-3-10 is about right. I use these types and add my own mix of trace elements which includes Ni which is vital if you use Urea.

Good to see you, Mike! The last time I looked into it, P can influence root growth indirectly in some species. High P discourage the development of mycorrhizal association. Plants without the association generally need to reallocate more resource toward roots. Low N also encourage the reallocation toward roots, too. And I agree P is requried by ANY living cells (e.g. to replicate DNA, transcribe to RNA, short-term energy source like ATP).

I don't see strong supports for the original idea of interference from K. But K-Lite (as well as whatever typical fertilizer) seems to work ok for me. I wouldn't say K-Lite is better or worse, and they both seem to work. As long as there is sufficient (and not excess) of each element, the composition of fertilizer doesn't seem to be too relevant. As with other environmental parameters, many (but not all) plants can flexibly acclimate to a fair range of growing conditions. After all, plants are sessil, so they can't choose the best environment. With K, different plant species have quite a bit of differences in the recycling rate. Orchids seem to have a high buffering capacity because they are super efficient for K recyclling. I don't know too much of cactus physiology, but I vaguely remember Tillandsia also high K recycling rate.
 
I think that there simply hasn't been enough research into the nutritional demands of individual orchids for anyone - including you and me - to say for certain what formula is "perfect" for what plants, and it can vary all over the map.
I agree entirely with this.
I ran a fertilizer trial many years ago using a K-Lite equivalent fertilizer over many different genera, and they all had different results. Cattleyas were out of control, hard cane dendrobiums new growths was too soft and collapsed in our hot weather. I stopped the program 2 years after starting because I couldn't keep up with repotting and dividing Cattleyas every year.
 
Actually, mineral analysis were done by the guy who use to frequently post here, (sorry I can't remember his name as I'm writing this). I think he was an adviser to big nurseries in Europe. His results for paphs collected from the wild and the ones cultivated showed that the ratio of N/K/Ca is pretty much 1 found in those plants. Nitrates and micros differed. According to him he paid all those lab tests. So let us just assume that paphs like any other orchid or plants need K. If you don't believe this then dismiss my comment below.
I consider K-lite as a supplement and not really a complete diet for plants grown in an in-organic media. When a media doesn't have any of the NPK and all other nutrients, one will have to provide all of them with the right ratio. The catch here is the media, nobody talks about what and how much are there available in them. Bark has lots of K and P already. The quantity differs when new and old and the source and type of bark. Google it. There are analysis and recommended supplements to balance the nutrients already found in them.

So depending on how much K is already in the media and or what is left and its accessibility to the roots (coarse vs fine) and the amount of Ca/Mg provided to extract K from the bark will probably dictate how much N is needed to balance N/K/Ca. Note that if Ca is used to extract/exchange K then Ca quantity requirements should cover for both the plant and the exchange.
Just an engineer's way of thinking.
 
I agree entirely with this.
I ran a fertilizer trial many years ago using a K-Lite equivalent fertilizer over many different genera, and they all had different results. Cattleyas were out of control, hard cane dendrobiums new growths was too soft and collapsed in our hot weather. I stopped the program 2 years after starting because I couldn't keep up with repotting and dividing Cattleyas every year.
My experience is the same but I was not using K-lite. I used a 2:1 (N:K) ratio for vandas and cattleyas. The vandas became lanky a bit but some cattleyas had soft stems/bulbs and were quite stretched that they bend over. I caught then just in time and shifted to low N. I noticed the big clumps on a wide pot full of big barks did not show any of this. But I was watching the back bulbs if they start dying.
 
I remember something I heard in a presentation from the company that makes the ProMix series of soils, that high-K leads to embrittlement of root cells, leading to decreased penetration by fungal mycelia, hence a reduced benefit in fungi supplanting nutritional uptake.

All of my paphs and phrags are in S/H culture, so they're getting very little, if anything from the medium. As I said earlier, they have been on K-Lite for a long time, and I sincerely believe that the KelpMax and Synergo (I sure wish they'd change the name already) are significant additions.

Echoing some of Naoki's comments, I think plants are somewhat flexible in their nutrient demands as long as they get "enough", but that remains mostly undefined.
 
I forgot to mention that I always add nutricote to all pots about 18-3-15 or something like that. I use liquids as a drench or spray to supplement that. But K is always ''high''. I have started adding nutricote with sand in teabags on top of mounted plants. Results are much better now showing that a constant trickle of nutrients works better than an occasional nutrient spray even if done weekly.
 
Ray, you have a good source of K from KelpMax. It just not advertized.
Diluted at 1:250 and applied monthly, KelpMax contributes 28 mg K per month. K-Lite, when applied at 75 ppm N weekly, contributes about 12x that, making the KelpMax contribution only about 7-8% of the total. I seriously doubt that's the "make or break" factor.
 
There's not much but your roots could be soaked in it for days(SH) to take all its needed. Unlike watering where the nutrients just flush out of the pot.
You might want to send a sample for analysis to verify the amount of K in your plants. If I am in business, that would be a good thing to do.
 
Last edited:
Thanks for a very stimulating and instructive thread!

But, geee, I'm glad, my plants can't read - as I would be at a total loss, not having the necessary natural scientific background to make and defend any drastic decissions in relation to their feeding regime!

I'll probably just have to stumble along with my helter-skelter, happy-go-lucky feeding regime of Pokon: NPK 20-20-20 + a variety of trace minerals x every 3-4 weeks -with the exception of the months of mid-november to end-january, where I don't feed, as the light up here north is pityfully low. During spring and summer supplemented with a monthly addition of a wee bit of magnesium sulphate.
 
Last edited:

Latest posts

Back
Top