kovachii culture; S/H, pH, and calcium?

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ssknapp777

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Hello All,

I’m a new member and I had questions concerning Phrag. Kovachii, S/H and PrimeAgra. I emailed Lance a few questions (OK, actually many questions) privately since it looked like he has posted a lot about kovachii and grows his in PA. He thought they were good questions and asked me to post them so when he replies everyone can see. This will be my first public post anywhere so I hope I do this correctly. If anyone else has anything to add/suggest/recommend please feel free.

Sincerely,

Shayne

____

OK, I noticed that your newer pictures have the crushed oyster shells on the top whereas your older pictures did not. Are your older kovachii from 06 still alive? Did you add oyster shells to them also? Or do you not need to after they reach a certain size?

I emailed Ray and he thought there might be enough calcium in the MSU Pure water formula but wasn't sure. Do you add the oyster shells for additional calcium or to raise the pH? If it is for calcium can you just add a calcium supplement?

That brings me to my biggest question that I hope you can answer. I've searched but can't find anything specific about pH of water and fertilizer solution and PrimeAgra. I can find the pH of the soil/medium kovachii naturally grows in (7.9), and I can find the pH of the rain water kovachii naturally gets (6-6.5). However, I don't know how to apply that to PrimeAgra. I understand the soil/medium will raise the pH of the water and I know kovachii likes more alkaline conditions whereas most other orchids need a slightly acidic environment to absorb nutrients.

I'm assuming that PrimeAgra will not adjust the pH up or down so we can limit/focus just on our water fertilizer mix pH. Since I've read kovachii likes slightly alkaline conditions could I/do you adjust the pH between 7-7.9? But then if so does this restrict the plant in being able to take in needed nutrients?

My thinking is also that maybe in its natural habitat the alkaline soil balances the acid in the water and the sum is slightly acidic and it can still take in nutrients? Maybe the reason why people are adding oyster/calcium chips and lime is to overcome the acidity of the medium and then the fertilizer/water solution they are adding.

It seems like there are so many possible variables and since you have much more experience with kovachii in S/H maybe you have figured out all this pH stuff. I did read that someone asked you about this but you had (I think) left your pH meter in Peru and had not been testing pH. I also read that you were just using the MSU at 50 ppm Nitrogen and then going to 100 ppm when they got a bit bigger. However my own testing of MSU and pH is that even the pure formula drops the pH down to the 5/6 pH range, of course this is using 125 ppm nitrogen.

Well, I hope this makes some sense, if it doesn't please ask for clarification. I guess to sum it up have you found the best adjusted pH value for your water and MSU RO formula mix that kovachii likes? Do you have to supplement calcium chips/oyster shells to the mix for older kovachii plants? If so is there a more elegant way/amount of adding calcium? Am I missing the point entirely concerning oyster shells and they are needed for another reason entirely.
 
Welcome from NYC. Mr. Norton, Orchidview, says Pk needs the calcium but its' hybrids don't need it as much. He also adds lime pellets but he says he's putting those on most phrags.
 
These days I'm really questioning the whole notion that the calcareous species (which includes many paph species too) have a special calcium need, but rather a special phosphorus need.

As I mentioned in a previous thread (probably several threads actually) limestone typically carries a fairly high stable phosphate level. Much higher than typical rain forrest soils and leaf litters. Also the mobility of phosphorus is much better in the neutral to slightly alkaline pH ranges than at lower pH's . P is also tied up easily by iron and aluminum, and once again at the lower pH levels. I read a paper about the productivity of crops grown in tropical soils, and it was enhanced by the addition of lime. As it turned out it wasn't directly due to calcium uptake by plants, but the pH increase unlocked the phosphorus tied up by iron and aluminum, and the calcium helped stabilize the phosphorus and facilitate it into the plants.

I also found several papers where oyster shell is able to suck up lots of phosphorus. I use it as a potting mix supplement to, and speculate that the phosphorus of the MSU fert mix (which has pretty low P compared to standard "balanced" fetilizers) is sucked up by oyster shell and the plants utilize the oyster shell as a long term source of P as the oyster shell slowly dissolves.

My multifloral paphs (which are mostly calcareous species too) really do good for me.

I would look into the use of bone meal rather than lime or oyster shell. I'm seeing lots of great growth since I top dressed allot of plants with it at the beginning of the growing season this year. Bone meal increases pH, but not as much as lime or oyster shell. It also adds allot of P along with the calcium.

I don't have kovachii, but I do have fisheri, which is another calcareous growing phrag. And so far they seem to be enjoying the strategy.
 
Thanks everyone for the warm greetings and welcomes!! Thanks also to Rick for the information on phosphorus. Ah, another thing to consider. Rick, what do you grow your fisheri in? Are they in S/H and Primeagra (PA)? Do you have a specific range for the pH of the water and fertilizer mix for calcareous species?

Since the PA should be inert and so I don't interfere with the wicking action of the PA, I'd like to attempt to add all needed nutrients of my orchids by liquid supplements. I'm not sure if this is possible but this is what I have in mind. Does anyone think this is possible? Or is it a bad idea?

Shayne
 
Thanks everyone for the warm greetings and welcomes!! Thanks also to Rick for the information on phosphorus. Ah, another thing to consider. Rick, what do you grow your fisheri in? Are they in S/H and Primeagra (PA)? Do you have a specific range for the pH of the water and fertilizer mix for calcareous species?

Since the PA should be inert and so I don't interfere with the wicking action of the PA, I'd like to attempt to add all needed nutrients of my orchids by liquid supplements. I'm not sure if this is possible but this is what I have in mind. Does anyone think this is possible? Or is it a bad idea?

Shayne

A newer one (growing for a few months now) is in a bark mix w/oyster shell top dressing. One I had for year + and beat up, I put into hydroton (with some oyster shell mixed in) a few months ago. It seems to be recovering with a new growth and leaves. The newer one is spiking now too. Even though its in a bark mix, I opened up the pot with more holes and keep it in a shallow tray of water.

I use RO for primary irrigation which has no buffering capacity, but with all the oyster shell in various potting mixes the pH of water in the catch pan should be about 7.0. I run the pH of my fertilizer mix up to around 6-6.5 with a dash of Protekt (KOH). The pH of the phosphorus boost I add intermittently to irrigation and misting water is about 6, but this is diluted way down when I use it.
 
was happy to see this thread since i'll be inheriting some k hybrids from recent trades. was doing dishes and the little light bulb popped on again; I remember at work having a conversation with one of the other growers about the pH of the water holding tanks that are used for floor/bench flooding/watering; they are concrete blocks and they said that the pH of the water held in these tanks climbs right along (they are basically lined with limestone from mortar). was wondering if concrete chips could be added a few here and there in pots or s/h culture to help keep the pH higher? water is definitely being raised in pH as it stands in the tanks.....
 
was happy to see this thread since i'll be inheriting some k hybrids from recent trades. was doing dishes and the little light bulb popped on again; I remember at work having a conversation with one of the other growers about the pH of the water holding tanks that are used for floor/bench flooding/watering; they are concrete blocks and they said that the pH of the water held in these tanks climbs right along (they are basically lined with limestone from mortar). was wondering if concrete chips could be added a few here and there in pots or s/h culture to help keep the pH higher? water is definitely being raised in pH as it stands in the tanks.....

Very weathered concrete may be fine, but some concretes have additives with them, and sometimes the lime content is really high. I'd stick with something more tried and true. I'd take a good look at bone meal first.

I do use allot of oyster shell, but I also live in the land of limestone down here in TN, and I also have quite a few pots of multifloral paphs with limestone chips in the bottom of the pots.
 
A very interesting thread.

I have read that the phosphorus demand of plants is actually quite low, and I know that was the reasoning behind the MSU formula's low level - it is intended for continuous feeding, after all - but just how low is it?

Rick's theory that oyster shell "captures" it and then the plants use the P and Ca as the shell bits dissolve would suggest to me that it is VERY low, as I imagine the oyster shell dissolves at a very slow rate.

Has anyone actually put oyster shell in pure water and measured the concentration of dissolved species as a function of time?

As an aside, I have some PK x besseae plants, some in S/H, some in a bark mix, both getting about 100-125 ppm N of the MSU RO formula at a pH of 5.8-5.9, and they are doing quite well.
 
A very interesting thread.

I have read that the phosphorus demand of plants is actually quite low, and I know that was the reasoning behind the MSU formula's low level - it is intended for continuous feeding, after all - but just how low is it?

Rick's theory that oyster shell "captures" it and then the plants use the P and Ca as the shell bits dissolve would suggest to me that it is VERY low, as I imagine the oyster shell dissolves at a very slow rate.

Has anyone actually put oyster shell in pure water and measured the concentration of dissolved species as a function of time?

As an aside, I have some PK x besseae plants, some in S/H, some in a bark mix, both getting about 100-125 ppm N of the MSU RO formula at a pH of 5.8-5.9, and they are doing quite well.

Based on the amount of P showing up in leaf digestion studies, the requirement for P is lower than for N and K is lower (rather than using the absolute term low), and yes the MSU mix is based on those ratios.

But going through the soil/ag and eco literature, this may be more of an adaptation to living in a chemical environment where P is limited compared to N and K. It also looks like the role of mycorrhizae fungi and bacteria in the rhizosphere become even more critical as soil pH drops below 5.5 - 6.0

Under SH conditions, using the MSU mix P is mostly likely not limited since the "soil" is virtually inert/neutral, and there is always a sump of nutrient rich water in the bottom of the pot to wick up from.

The P deficiencies are more likely to show up in bark mixes, especially as they break down, and become even more acidic. In these cases P enters the system intermittently (through a weekly feeding), and has the potential to get tied up by the soil conditions.

I did conduct one experiment (not quantified) where I placed about a tablespoon of oyster shell into RO water (I think about a liter), shaking intermittently the pH and hardness (indirect measures of Ca and Mg concentration) where very high in roughly twelve hours. I posted this result on a thread about oyster shell a couple of years ago so I can't remember the numbers. At the time I wasn't aware of the P absorption capacity of oyster shell so I didn't try soaking oyster shell in dilute phosphoric acid to try that idea out. But it's apparent that oyster shell can give up Ca at a pretty decent rate in acidic conditions, and soil microbes would facilitate this even more. Actually there are lots of ag papers that show how oyster shell and lime boost soil pH, and a paper published in AOS on oyster shell addition in bark media boosted soil pH. We debated that paper on this forum (that may be where I did the oyster shell/RO water trick). The fast P adsorption phenomena by oyster shell is well documented (Google search if you like). So I don't think its too far fetched to put the two ideas together that oyster shell could be a sump for P in a standard bark mix the same as the sump in a SH system works.

On a new side note/theory. Since I've been messing around with increased P I've noticed a decline in blue-green algae in my SH style systems and algae covering up mosses. The mosses are doing much better, and losing the overgrowth of blue-green slime.
 
In the category "there's more than 1 way to shin a cat".

Refer to Marilyn LeDoux's article on growing phrags in OD, 2003.

She advocates the use of a fertilizer "such as Dyna-Gro" (7-9-5 versus MSU 15-5-15), and a bark mix formula that includes bone meal (another big P boost).

I don't think anyone could argue that Marilyn knows how to grow phrags.

Also in review of Sanderianum's 5/08 thread on paph nutrition he advocates the use of a 10-52-10 fertilizer, but also states that a source of "carbonate (such as calcium carbonate)" is necessary in the potting mix. Since oyster shell is primarily CaCO3 this alludes to my "theory" that oyster shell acts as sink for P in bark or CHC based mixes.

The more I read keeps pointing to how easy it is to maintain a good N and K budget, but P balance is real easy to screw up.


Recently there was some excitement about some type of SH media that caused allot of growth problems. If I'm not mistaken most SH medias are clay based, and clay is primarily formed of Al and Fe silicates. Al and Fe are general P binders, and a product called activated aluminum is especially effective at binding P. Is it possible that this product had "activated" Al in it, and essentially caused a nutrient imbalance??
 
A very interesting thread.

I have read that the phosphorus demand of plants is actually quite low, and I know that was the reasoning behind the MSU formula's low level - it is intended for continuous feeding, after all - but just how low is it?

shoot. I was trying to upload a link to a Springer article that I saved the abstract from. Try www.springerlink.com/content/p5w1u6277832152x/

It's just the abstract, but the gist is P leaf contents of species studied (tropical plants in 2 different serpentine areas) varied on the basis of nutrient restriction rather than physiological need, while K, Mg, and Ca, content were based on physiological need rather than soil availability.

So the premise that P in the MSU formula (derived from leaf content analysis of a limited number of orchids) is the correct and physiological need based level of P for all orchids is strongly challenged by this article.

But I don't think this is that new of a debate.
 
Is P translocatable between leaf cells, and is it "dumpable" by a plant? And I suppose that f the answer to either is 'yes", then the rate might be important, too.

Rhetorical questions, but I wonder if the percentages in leaf analyses reflect the current nutrient flux are are just an accumulation/time lag - or as you said earlier, an adaptation for "lean times".
 
Is P translocatable between leaf cells, and is it "dumpable" by a plant? And I suppose that f the answer to either is 'yes", then the rate might be important, too.

Rhetorical questions, but I wonder if the percentages in leaf analyses reflect the current nutrient flux are are just an accumulation/time lag - or as you said earlier, an adaptation for "lean times".

That may be a critical question Ray. I'm not sure how much P is incorporated into cell "structures" versus its use in cell metabolism. My current knowledge of P is that it is primarily used for metabolic function (the ATP pathways). That could imply that it's content is quite variable given a plants energetic state. An analogy may be like gasoline to a car. Is the plant idling, accelerating? Under conditions of acceleration (growing, blooming, rooting, fighting disease), the gas needs to be there to keep from running lean and stumbling. If the plants just idling it takes hardly any gas.
 
This has turned into a very good discussion. Thanks everyone.

This P vs. Ca and what function the oyster shells are actually performing is exactly what I hoped to find out from people. I have learned it might not just be Ca but maybe additional P is needed. It almost seems like we need to experiment a bit. Start with a neutral media (PA) and a pure water source (RO, distilled, clean rainwater), and fertilizer (lets go with MSU RO). Adjust pH to between 7-7.7, (or is this too high for kovachii?). This could be our baseline. Then we would just need to change the variables in a controlled way. Is it Ca? We could have a pure Ca supplement (add 1 ml for x duration) note results, we may have to increase or decrease amount of Ca in ml over time. Go back to our baseline, instead of adding/adjusting a pure Ca supplement add a P only supplement. Monitor plant. Although there might be too many other variables e.g. more light one day or over a period of time than another. I guess it would also be too time intensive. But it seems like you sure could tailor to exactly what the plant needed over time with lots of experimenting.

It seems like others are doing this for lights and hydroponics. When I was researching LED grow lights I found a guy that was reviewing these lights you could buy. The produced lights already moved away from a full white spectrum and was just red and blue. However, the reviewer noted that growth vs. blooming of plants needed different ratios of blue to red LEDS. So now he & others are building their own lights so blue LEDs are on a different circuit than the red LEDS and he can adjust the intensity of the blue vs. the red depending on the stage of growth the plant is in. All very interesting and similar to us adjusting and fine tuning a specific chemical need of orchids.

Shayne
 
Not exactly sure if I understand where you are heading with this one Shayne. Is your basic question to optimize growth of PK under semi hydro or more general conditions? I think there are multiple ways to get PK to grow well, and there are a ton more variables to worry about besides Ca an P balance.

I am a much stronger proponent of providing proper humidity/airflow/light and temp regimes before fine tuning with potting mixes and fertilizers.

Also I don't know who has a few dozen spare PK to set up in controlled experiments.

But there is an Ag experiment with a link access in one of Sanderianum's posts (the thread is "CHC or not to CHC" I think) which may give you some good ideas.
Ca (from gypsum, CaSO4) was used as a Ca source in some of these experiments. There is no practical source of elemental Ca. Many pure elemental forms of light metals are extremely unstable (often explosive). So you will most likely need to content yourself with either the SO4, NO3, Cl, or Phosphate forms of Ca.

I'm wondering if it might be a good exercise to set up two groups. One with standard SH with PA, and one with PA washed in phosphoric acid.
 

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