# SH update



## Eric Muehlbauer (Jan 2, 2007)

Well, its a new year, and I've have now been growing some plants in SH for 6 months or so...so I felt I could now give an update on my experience. I used the old Prime agra from Ray...I only planted a very few paphs in SH...so far, not thrilled. A Maudiae type immediately responded with increased leaf turgor (a universal response, I must admit...)...but no growth of any kind. When I brought it indoors, it died within weeks...post-mortem showed no root growth at all, and fewer roots than when first planted....another paph, Henrietta Fujiwara, has been stable...no growth on top or bottom. My one success was Paph Honey....lots of root growth, but no really major top growth. My biggest surprise was with phrags...i expected them to really take off. Instead, I saw nothing impressive for the most part. Leaves are good, but growth was slow to average...with no really visible new root growth. Only 2 phrags responded with vigorous root growth, growing throughout the media, into the reservoir, and adding lots of new leaves. Still, this is not anything more than I see in my usual phrag bark mix..I did not fertilize them more than other phrags, and continually topped off with fresh water. My phrag fertilizer is straight MSU,about 1/4 tsp/gal, weekly in summer and under lights, bi-weekly in winter, plain water about 5 days/week. I found that SH needs watering (for phrags) about as frequently as my bark based plants...Only 2 non-slipper plants went into SH...and here I was VERY impressed...an Odontioda hybrid filled the rocks with roots, and I eventually plan to put my other similar crosses into SH. A phal schilleriana has been in SH only about 2 months, and already has shown better root growth than I have seen on a phal in years. I definitely plan to order more Prime Agra, after my wallet recovers from the holidays...I have to admit that it is certainly easy and fast potting, even though I don't find those plastic cups and chinese take-out soup containers to be attractive pots...and I will continue to experiment with it...certainly, while I have not been impressed by phrags in SH, none have done badly...just not as good as expected, for most. I think eventually, all my odont's will go into SH, and I'll continue to use it on phrags, if only for convenience. I will occasionally use it on paphs...I certainly didn't try it on enough to really know....and I'll continue to post updates as I gain experience...Take care, Eric


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## bwester (Jan 2, 2007)

I found mine grew almost no new roots. The plants grew (on the old stuff),, but they seemed content with the roots they had.


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## gonewild (Jan 2, 2007)

I think with the inert inorganic nature of PrimeAgra you need to increase your fertility levels. Remember there is no nutrient holding capacity in the clay pellets whereas organic mixes will hold nutrients for the plants. 

The s/h method relies on constant additions of nutrients. One flush with clear water will reduce your nutrient levels to near zero in PrimeAgra. 

Lack of nutrients could certainly explain your results of little or no growth.


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## Heather (Jan 3, 2007)

I try to fertilize every time I water and I have many plants with new growth and much new root growth. I'm actually quite happy with all of my plants in Prime Agra. Anything that was root challenged before, still is, unfortunately, but it was before.


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## NYEric (Jan 3, 2007)

Thanks for the info. I'm going to keep using it in a mix. The plants I got from Lance, Heather, and Eric M. that I will keep in PrimeAgra are in water circulating so there may be some algae growth and therefore the mix isn't inert. If I find problems I will change the mix and keep the forum abreast.


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## Eric Muehlbauer (Jan 3, 2007)

Actually, I never flush the mix....I simply top it off to fill the reservoir...sometimes I pour out the water before adding the fertilizer solution. I'll try increasing the concentration on the SH phrags...although, as I said, the the odont and phal that are doing so well get the same fertilizer concentration as the phrags...the paphs get higher, with a touch of Pro-Tek to raise the pH. FWIW, the 2 phrags that are doing best are hybrids.....the only species I have in SH are pearcei and beseae...too soon to tell with besseae, because it has only been in SH for about a month. I do add prime agra to my CHC paph mix....but that is for a different purpose, not SH...Take care, Eric


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## SlipperFan (Jan 3, 2007)

About 4 years ago, I placed all my Phrags in PrimAgra S/H. Some took off and did really well -- even got one awarded. But after 2-3 years, upon repotting, I found most of them were losing roots, badly. A few were still quite good, so I repotted them the same. But the others, I've placed in a diatomite/chc/spongerock mix I made up, and most seem to be recovering.

Before I discovered the declining roots on the Phrags, I placed most of my Paphs in PrimeAgra S/H. I checked them after 6 months and found that most were declining. So now they are in a similar mix to my Phrags.

I have two Psychopsis in PrimeAgra S/H and they love it. I've tried Zygos in it, and they seemed to do well, also. I have a few things in S/H diatomite right now, but not long enough to know whether successful or not.

I don't understand why some think you need more fertilizer with PrimeAgra. It hold/transfers water at least as well as bark, so why wouldn't it hold/transfer the fertilizer that is in the water?


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## gonewild (Jan 4, 2007)

SlipperFan said:


> I don't understand why some think you need more fertilizer with PrimeAgra. It hold/transfers water at least as well as bark, so why wouldn't it hold/transfer the fertilizer that is in the water?



You don't really need more fertilizer with PrimeAgra you just need it applied more often.

The reason has to do with an amazing "banking" system in nature. Soils take deposits of nutrients and hold them for plants to withdraw at a later date. (Just like humans do with money in a bank.)

It is not the water holding capacity that influences the nutrient holding capacity of a mix but rather a process known as cation exchange. I'll try to explain it.

Cation exchange has to do with positive and negative ionic charges of the elements involved. Soils (mix) that contain clay and/or organic matter (bark) have a *negative* energy charge. Plant nutrients generally have a *positive* energy charge when dissolved in water. When you water a pot with _fertilizer water_ the negatively charged organic matter grabs hold of the positively charged fertilizer and binds it to the mix, thus removing it from the water. (Like taking money from your hand and putting it into a bank vault) 

After this happens the water passes on and out the bottom of the pot and leaves the mix "fertile". Plant roots have the ability to reverse the ionic hold the organic matter has on the nutrient molecule and take it into the plants system for growth. (See it is the same concept as depositing and withdrawing money from a bank vault.)

PrimeAgra is made from clay which has a very high cation exchange capacity but when the clay is heated, to make the pellets, the negative charge of the clay is destroyed and the pellets become inset and have zero cation exchange capacity. (the bank no longer has a vault to keep money)

So organic mixes have the ability to store plant nutrients. 
Inert mixes such as PrimeAgra have no cation holding capacity and do not store nutrients for later use by plant roots.

Does this help you understand why you need more fertilizer with PrimeAgra?


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## bwester (Jan 4, 2007)

wow, i actually agree with Lance on this one oke:


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## gonewild (Jan 4, 2007)

bwester said:


> wow, i actually agree with Lance on this one oke:


That's because I left out the part about the whole thing really being a magical herbal process. oke:


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## bwester (Jan 4, 2007)

damn it Lance, quit trying to sell your tiger penis herb on our forum :rollhappy:


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## gonewild (Jan 4, 2007)

bwester said:


> damn it Lance, quit trying to sell your tiger penis herb on our forum :rollhappy:



Um..... tiger penis is not an herb. But I bet it has a good cation exchange capacity.


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## SlipperFan (Jan 4, 2007)

gonewild said:


> After this happens the water passes on and out the bottom of the pot and leaves the mix "fertile". Plant roots have the ability to reverse the ionic hold the organic matter has on the nutrient molecule and take it into the plants system for growth...Does this help you understand why you need more fertilizer with PrimeAgra?


This makes sense if PrimeAgra is used as the media in regular pots. But if it is used in s/h pots, i.e., pots that have a well at the bottom which holds the fertilizer water, it doesn't make sense. In these pots, the fertilizer/water is gradually wicked up by the clay pellets.


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## gonewild (Jan 4, 2007)

SlipperFan said:


> This makes sense if PrimeAgra is used as the media in regular pots. But if it is used in s/h pots, i.e., pots that have a well at the bottom which holds the fertilizer water, it doesn't make sense. In these pots, the fertilizer/water is gradually wicked up by the clay pellets.



That is correct, if you follow the true method of s/h culture and always irrigate with water containing a constant level of nutrients.

But if you water once with clear water you have flushed out or diluted the nutrient rich water and replaced it with zero nutrient content. Because the PrimeAgra has no cation exchange capacity there would be little nutrients for the plants until you once again add fertilizer water.

In the organic mix the roots are getting nutrients that are bound to the organic matter and not entirely from the fertilizer water itself. With PrimeAgra the roots take the nutrients entirely from the water that is wicked through the media.

In Eric's case he is using the same fertilizer strength in PrimeAgra as he uses in his organic mix. Because the organic mix holds and accumulates nutrients a weaker fertilizer solution will maintain the required nutrient levels needed for uniform constant growth. 

So if you grow in bark and get good results with 1/4 tsp fertilizer per gallon applied every two weeks you won't likely get the same results in growth if you use the same strength in PrimeAgra. The plant will constantly be falling short of needed nutrients. When nutrients become in short supply plant growth slows or stops. With PrimeAgra you need to compensate for the lack of stored nutrients by increasing the amount of nutrients in the reservoir water.

It's all about keeping the food supply constantly available at the optimum balanced levels at all times.

Does this make more sense?


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## SlipperFan (Jan 4, 2007)

gonewild said:


> Does this make more sense?


That's very interesting, Lance. Until you explained all this, I always thought I was over-fertilizing in my s/h PrimeAgra pots. When I was growing my Phrags that way, I had a lot of leaf tip browning, and after a couple of years the roots started rotting. Again -- I thought this was perhaps over-fertilizing. I used MSU rainwater fert. with rain water, at the recommended strength.


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## gonewild (Jan 4, 2007)

SlipperFan said:


> That's very interesting, Lance. Until you explained all this, I always thought I was over-fertilizing in my s/h PrimeAgra pots. When I was growing my Phrags that way, I had a lot of leaf tip browning, and after a couple of years the roots started rotting. Again -- I thought this was perhaps over-fertilizing. I used MSU rainwater fert. with rain water, at the recommended strength.



Do you know what the recommended rate you used was?
Do you know what the total ppm was on your water/fertilizer solution?
Do you know for sure your rainwater is pure and mineral free?

Following a recommended rate is not always the best idea. Not all plants are going to tolerate the same salt levels, so making a standard recommended rate is only a general guess for the correct level. 

When you first grew in PrimeAgra did you have problems with leaf tip browning or did it begin to appear after some amount of time? Maybe the leaf problem was a result of a root problem?

You said after a couple years the roots began to die. Had you ever repotted the plants or were they in the pot for a couple years undisturbed?

I don't know how long it is reasonable to expect an individual root to live.


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## bwester (Jan 4, 2007)

plus rainwater doesnt get anywhere near pure until theres been at least 30 minutes of good downpouring. For that first 30 minutes or so, you're getting the excrement of the earth's air filter.


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## gonewild (Jan 4, 2007)

bwester said:


> plus rainwater doesnt get anywhere near pure until theres been at least 30 minutes of good downpouring. For that first 30 minutes or so, you're getting the excrement of the earth's air filter.



Good point.
Do you think that even after 30 minutes the rain water is really pure? 
Or is all the water vapor in a storm front also contaminated?
How would the contaminants relate to problems for plant growth?


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## SlipperFan (Jan 5, 2007)

I'm getting dizzy......... (We need a dizzy smiley, Heather...)



gonewild said:


> Do you know what the recommended rate you used was?
> Do you know what the total ppm was on your water/fertilizer solution?


It's calculated for 120 parts per million N.


gonewild said:


> Do you know for sure your rainwater is pure and mineral free?


Minerals coming off the roof? Maybe silica? My Paphs and other orchids have been fine with this water. And now that I've repotted the Phrags, most of them seem fine, as well. Some more than others, but I have about 110 or them, so that is not surprising.

Interesting to note that recently a commercial grower of Paphs, Bulbos and other orchids in Florida visited my home. He talked about having a problem with tip burn, sending his plants in for analysis several times, and after finding nothing, did a little sleuthing himself and found that it was because the media was holding to much fertilizer salts and linked that directly to the tip burn. Now please understand that this is a very brief summary of what he said to me.


gonewild said:


> Following a recommended rate is not always the best idea. Not all plants are going to tolerate the same salt levels, so making a standard recommended rate is only a general guess for the correct level.


Well, I work for an orchid nursery that had one of the professors behind the MSU formula come out and test our rainwater. Then he modified the MSU formula for use with rainwater, RO and distilled water. All 3 are slightly different, but then so is ground water when used with the formula for tap/well water. This nursery was the first to package and sell the MSU formula, but since an article came out in Orchids Magazine a couple of years ago with the formula, and it started selling very well, now everyone has it. And that is good.
I cut back to about 100 ppm N in the colder, darker months, btw.


gonewild said:


> When you first grew in PrimeAgra did you have problems with leaf tip browning or did it begin to appear after some amount of time? Maybe the leaf problem was a result of a root problem?


I truly don't remember. I actually think it has more to do with a lack of humidity than anything else.


gonewild said:


> You said after a couple years the roots began to die. Had you ever repotted the plants or were they in the pot for a couple years undisturbed?


They were in the same pots, undisturbed for a couple of years or so.


gonewild said:


> I don't know how long it is reasonable to expect an individual root to live.


If there had been new root growth, I'd not have worried or changed my approach.


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## Eric Muehlbauer (Jan 6, 2007)

By the way...I made a mistake in my description of my fertilizer regiment...I use 1/2 tsp MSU/gal on my phrags, phal and Odta, not 1/4 tsp.....I'll try more frequent fertilizing, although, as Heather pointed out in another thread, coming home late from work, after dark, its a lot easier to just top of the reservoirs with plain water as I water my other phrags. Take care, Eric


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## gonewild (Jan 6, 2007)

How you water probably has a big influence on the total salts in the pots. if your plants run on the dry side you will need to watch for salt problems more than if they are kept wet. Plants absorb nutrients through their foliage so I like to get them wet with nutrient rich water as often as possible.

Keep in mind also when using MSU fertilizer at a target rate of 125 ppm nitrogen a slight mis-measurement may put the total salts level higher than some phrags may tolerate well. 

The label of the MSU brand I'm using says to use 1 teaspoon (4.3 grams) per gallon to achieve 150 ppm nitrogen. But when dealing with ppm a "teaspoon" is not an accurate measurement. My average teaspoon scoop actually weighs 5.2 grams which is a 20% overdose! The coarseness of the dry fertilizer will greatly influence the weight even a carefully measured scoop.

4.3 grams of MSU fertilizer per gallon of water yields 605 ppm total salts in RO water whereas 5.2 grams of MSU fertilizer per gallon of water yields 721 ppm total salts.

605 ppm is probably OK for phrags and 721 ppm is probably to high for sensitive species. I don't know if anyone knows the real tolerance level?

So be careful to measure fertilizer amounts and water amount correctly, especially for S/H culture where the roots are constantly in the solution.

I mix 2 tablespoons MSU fertilizer in 8 gallons of water and the plants are growing well. (3/4 tsp per gallon)


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