# Are CHC ok or...



## Stone (Apr 30, 2012)

What are your experiences with chc. I'm kind of in two minds about them.
Pros: Hold moisture well
Hold the plant stable
Paph roots seem to like attaching to them
They seem to have good physical properties
Cons: They have bad chemical properties (High K, High Cl, Low Ca, S etc.
They start breaking down quickly
Hold too much water?
So is there a technique in correct use? Maybe feed at a much reduced rate?
Some recommend treating with Gypsum, Some with Calcium sulphate and Magnesium sulphate. An orchid growing friend told me he weathers them for a year in the rain before using them and has good results. An orchid nuseryman stopped using them because he believed they released toxins after a year or so but I suspect it is a build up of fert. salts or too much K released when they start decomposing?
Anyone have good LONG TERM results?

Mike


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## ehanes7612 (Apr 30, 2012)

have no complaints..as long as you keep the bottom third or so of the pot with well drainage material ( like styrofoam) ...i also go very light on the K anyway..ive had roths growing in 3 year old mush of chc doing great


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## Rick (Apr 30, 2012)

My personal experience has ebbed and flowed with the stuff over the last 10 years.

As far as paph growing, it was kind of a group specific thing. Multi's did great as long as they were potted real tight (like a 24" plant in a 2 inch pot!). Barbata types did crap no matter what.

Big Catts did great (as well as the lower 1/3 of the pot was filled with peanuts).

Seedlings of just about anything did crap.

If you pretreat soak them with lime/epsom salts (kind of like the Orchiata bark treatment) you get a big head start from them. Off the top, high quality washed and pretreated CHC is not significantly different from bark as far as chemical content, and I think superior to bark on moisture holding content. But it really likes to suck up and retain the monovalent cations (of which most people pour on the K, making it a big K sink).

Since coming up with the low K feeding regime, I've been trying out groups of seedlings (lowii and callosum) in CHC mixes, and so far they are doing fine.

By now the callosums would already be on the skids, but they are actually looking pretty good so far.

So I'm not on the verge of a wholesale shift back to a CHC mix like in the past, but it looks like I can control its worst attributes effectively. I'm still liking my basket system more than standard potting methods, but will use a CHC mix to pot up a bunch of newbies that I plan on dispersing after a few years.


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## keithrs (Apr 30, 2012)

Rock, LECA, Orchiata, and CHC are my substrates of choice!!! I have one Paph in CHC with a mixture of LECA and pumice. I must say, its doing well... I keep it moist all the time.


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## Eric Muehlbauer (Apr 30, 2012)

CHC is great for cattleya alliance...they fill the pot with roots, and I use no drainage material whatsoever...just straight CHC, nothing else. Larger dendrobiums and oncidiae love it also, as do Vandas. Pleurothallids and phals hate it, as do phrags. Paphs fool you...they appear to like it at first, then go downhill. Its probably good for them if you are willing to repot 2-3 times a year. Barbata especially hate it. Some of the multi's, however, can do quite well in it...philipinense in particular...but lowii and haynaldianum hate it. Brachy's also can tolerate it fairly well, so salts are definitely not the issue...besides, I soak it multiple times, including a soak with CaNO3 and MgSO4.


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## cnycharles (Apr 30, 2012)

my phals would do okay for a little while and then look bleached and unhappy. my only real success was my nice paph delenatii that was very loosely potted in med. chc with sponge rock and charcoal, could be without water for a while and was very happy. when I started trying other things and put a bunch of stuff in lots of rockwool cubes, it became very unhappy. so, even if k-lite does improve things a lot i won't go back to it as i think orchiata will be much better for me


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## tenman (May 1, 2012)

CHC is great! Everything does well in appropriate mixes with it. It lasts 3-5 years versus 1 for bark, perhaps 2 for really large bark in catts. I use larger CHC with #4 spongerock for catts, loosely potted and clipped/staked for security, in clay pots. Oncidiums, dens, and such are in small chc/spongerock; oncid group in plastic pots, dens in clay. For Phals, phrags, and larger-pot paphs (all in plastic pots), I use med to large CHC with hand-chopped (not milled) sphagnum and spongerock. For paphs in pots 3" or smaller, I juse the same mix with small CHC instead of the large. For bulbos and terrestrials I add some peat-based stuff (promix or commercial peat potting 'soil') to the small chc mix. Masdevallias, miltoniopsis, almost all my plants are in it - except some oddities - and the 200+ trichopilia plants, which have been in straight sphag the last couple years. It's a huge improvement over bark; I can repot every couple to three years, depending on the plant, and that saves me so much time.

I use MI formula fert, .5tsp/gal, every other watering or so, and the last six months have been subbing epsom salts (1 tsp/gal) for fert once a month or so.


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## Ray (May 1, 2012)

tenman said:


> CHC is great! Everything does well in appropriate mixes with it. It lasts 3-5 years *versus 1 for bark, perhaps 2 for really large bark in catts*.


You, sir - OBVIOUSLY - have not tried Orchiata!

Based upon what I've seen over the past two, I think 5 years will be easily doable (as long as you flush well and use K-Lite or the like to slow mineral buildup), and have heard some Hawaiian growers (they've had it for years) say 10.


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## emydura (May 1, 2012)

I had a lot of Paphs growing in CHC but in the end I went back to bark. I just found root growth was too inconsistent. Some went OK but too many plants had poor root growth, which is not such a problem for bark with me. Roots would grow for 5-10 cm and then just die off. Now that I have my fertiliser sorted, I'm happy using bark in combination.


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## Mrs. Paph (May 1, 2012)

I was much happier with CHC's when growing up north (North and South Dakota) I'm not pleased with how long it lasts now, living in OK and TX the last ~5 years. It just seems to get soggy and not dry out. Now I have of course been adjusting how much hydroton and things like that to the mix, especially toward the bottom of the pots, but still not entirely happy with it's performance with general indoor growing temps being warmer and more humid than up north. I am considering Orchiata, but am repotting at least for one more year in CHC because I got a large bag of it a few years ago and would like to at least put a dent in it... I've been using CHC pretty much from the 2nd or 3rd orchid I bought, so over 10 years, and I've always sucked at Barbata and rocked at Multis!!! Coincidence?!?  Damn, now I need to convince my husband I should order some Orchiata and the shipping costs...


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## Paphman910 (May 1, 2012)

I use CHC for all my Paphs and it is more of an admendment to a mixture of sphagnum, perlite, charcoal, dolomite, crush coral and limestone chips. My Paph stonei really likes this mixture and I top dress it with dolomite yearly. I also use alot of lava rock to increase the drainage as well.

CHC was rinse at least 30 times over 2 months until the water become almost colorless with a hint of tan color. By now they all sink and is fully hydrated so the salts would have somewhat leeched out. Then I soak with Ca nitrate and epson salt in my last 2 rinses.

I included a picture of my stonei plant that was repotted on April 30, 2012.

Paphman910


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## Rick (May 1, 2012)

Mrs. Paph said:


> I was much happier with CHC's when growing up north (North and South Dakota) I'm not pleased with how long it lasts now, living in OK and TX the last ~5 years. It just seems to get soggy and not dry out. Now I have of course been adjusting how much hydroton and things like that to the mix, especially toward the bottom of the pots, but still not entirely happy with it's performance with general indoor growing temps being warmer and more humid than up north. I am considering Orchiata, but am repotting at least for one more year in CHC because I got a large bag of it a few years ago and would like to at least put a dent in it... I've been using CHC pretty much from the 2nd or 3rd orchid I bought, so over 10 years, and I've always sucked at Barbata and rocked at Multis!!! Coincidence?!?  Damn, now I need to convince my husband I should order some Orchiata and the shipping costs...



What is your feeding regime, and what is the chemistry of your dilution water?

You should try K-lite if not already because the CHC acts like a potassium sponge, and raises the salt levels in the potting mix pretty quick.


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## Stone (May 1, 2012)

emydura said:


> I had a lot of Paphs growing in CHC but in the end I went back to bark. I just found root growth was too inconsistent. Some went OK but too many plants had poor root growth, which is not such a problem for bark with me. Roots would grow for 5-10 cm and then just die off. Now that I have my fertiliser sorted, I'm happy using bark in combination.



Just thinking about the differences between pine bark and coconut, bark will usually only hold moisture (and therefore salts) on its surface or at most a couple of mm into the surface (until it begins to break down), whereas with chc the entire particle becomes saturated with water and the salts it contains so if we assume that it can hold say at least 100%? (maybe 200%?) more water than bark, we should also asume that we should cut nutrient levels by the same amount?
When we flush bark with plain water we go a long way towards removing previous nutrient additions but can we assume the same with chc?
If the above is true, we can't use the same techniques with bark and chc and expect the same results.
So why do my Catts do well in it??


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## eggshells (May 1, 2012)

They say Catts are heavy feeders maybe they just tolerate salts better than paphs.


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## Stone (May 1, 2012)

Paphman910 said:


> > CHC was rinse at least 30 times over 2 months until the water become almost colorless with a hint of tan color. By now they all sink and is fully hydrated so the salts would have somewhat leeched out. Then I soak with Ca nitrate and epson salt in my last 2 rinses.
> 
> 
> 
> Thats a lot of prep! What % chc in the mix? How much feed?


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## Stone (May 1, 2012)

eggshells said:


> They say Catts are heavy feeders maybe they just tolerate salts better than paphs.



Probably, maybe also the drying out has something to do with it?


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## Rick (May 1, 2012)

Stone said:


> When we flush bark with plain water we go a long way towards removing previous nutrient additions but can we assume the same with chc?



Apparently not. The ion exchange capacities of bark and CHC are different and not just related to the surface area.

Without having a decent concentration of divalent ions available in solution, the CHC (and to some extent bark and moss to) will selectively hang on to the potassium and sodium during flushing.

Big fast growing plants (like Catts) are able to handle/use more K than seedlings or slow growing paphs.

But despite the "success" of my long term Catts in CHC, I was surprised at how much they improved after taking my foot off the K pedal and pushing on the Ca/Mg.


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## Stone (May 3, 2012)

Well after a 4 hour web search with eyes hanging out of my head, It seems that ST has the latest and most up to date info on chc that I can find.

There is lots of conjecture and dissagreement.
One old thread mentioned hormones as a source of trouble. I thought plant hormones are organic molecules and as such will break down fairly quickly by bacterial action. That's why they tell you to keep rooting compound in the fridge.
I also read many times about good results initially then a downhill slide. There are only a couple of reasons that _I_ can see that could cause this. 1 some toxin released with decomposition--seems unlikely? 2 Build up of salts caused by fertilizer---very likely. 3 Imbalance with K-Ca-Mg. and Fe?

So you wash and you wash and you rinse and you rinse and when you're finished you thow it away and go back to bark:rollhappy:


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## Ozpaph (May 3, 2012)

Paphman910 said:


> I use CHC for all my Paphs and it is more of an admendment to a mixture of sphagnum, perlite, charcoal, dolomite, crush coral and limestone chips. My Paph stonei really likes this mixture and I top dress it with dolomite yearly. I also use alot of lava rock to increase the drainage as well.
> 
> CHC was rinse at least 30 times over 2 months until the water become almost colorless with a hint of tan color. By now they all sink and is fully hydrated so the salts would have somewhat leeched out. Then I soak with Ca nitrate and epson salt in my last 2 rinses.
> 
> ...



Superb root system. What are your mix proportions?


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## Ray (May 3, 2012)

Stone said:


> <snip>One old thread mentioned hormones as a source of trouble. I thought plant hormones are organic molecules and as such will break down fairly quickly by bacterial action. That's why they tell you to keep rooting compound in the fridge.</snip>


It's not degradation by bacteria that's the storage issue, it's heat and light. The synthetic rooting hormones are very chemically unstable. Kept cold and dark, a freshly-manufactured batch is good for about a year. Add them to an exposed concentrate tank in your greenhouse, and it's a matter of days, if not hours.


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## keithrs (May 3, 2012)

I rarely rinse or soak my CHC any more and I have had no problems with it.... I pot up dry and give a good watering with a wetting agent.


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## Rick (May 3, 2012)

Stone said:


> 2 Build up of salts caused by fertilizer---very likely. 3 Imbalance with K-Ca-Mg.



points #2 and #3 are esentially the same thing.


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## Stone (May 3, 2012)

Ray said:


> > It's not degradation by bacteria that's the storage issue, it's heat and light.
> 
> 
> 
> Yes of course! you are correct. But even so what hope do any natural plant hormones have of surviving for long once degradation begins? Some bacteria can make short work of even some pesticides and herbicides.


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## Stone (May 3, 2012)

Rick said:


> points #2 and #3 are esentially the same thing.



Yeah kind of. I was thinking more of general rise in salinity as opposed to specific imbalances.
On a related issue, I found a reference stating: (when treating products for p/mix production) '' All media based on peat, coir, and wood wastes MUST recieve Iron as sulphate @ 600 to 1000gms/cubic mt. ( for bark and coconut ) and Copper as sulphate @ 10 to 30gms/cubic mt. on top of Ca. and others as need is shown by analysis. So maybe chc should be properly prepared as raw pine bark is (including a period of composting)

When I get my hands on fresh t/fern fiber, I soak in Lime and Iron sulphate then let sit moist for a month. (after washing) It's then ok!


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## Rick (May 3, 2012)

Stone said:


> Yeah kind of. I was thinking more of general rise in salinity as opposed to specific imbalances.
> On a related issue, I found a reference stating: (when treating products for p/mix production) '' All media based on peat, coir, and wood wastes MUST recieve Iron as sulphate @ 600 to 1000gms/cubic mt. ( for bark and coconut ) and Copper as sulphate @ 10 to 30gms/cubic mt. on top of Ca. and others as need is shown by analysis. So maybe chc should be properly prepared as raw pine bark is (including a period of composting)
> 
> When I get my hands on fresh t/fern fiber, I soak in Lime and Iron sulphate then let sit moist for a month. (after washing) It's then ok!



That may be worth trying. I would certainly emphasize the lime more so than the iron and copper. At the lower end of those ranges your addition rate (as metal)is maybe 200 mg/L of Fe and 5 mg/L copper. That's plenty to kill off any mollusc or insect life in the stuff, but after washing and lime, it should be fine for plants. Do you use ferric or ferrous sulfate?


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## Stone (May 3, 2012)

Rick said:


> That may be worth trying. I would certainly emphasize the lime more so than the iron and copper. At the lower end of those ranges your addition rate (as metal)is maybe 200 mg/L of Fe and 5 mg/L copper. That's plenty to kill off any mollusc or insect life in the stuff, but after washing and lime, it should be fine for plants. Do you use ferric or ferrous sulfate?



Ferrous sulphate. Turns organic materials (bark etc.) dark brown/black.


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## Rick (May 3, 2012)

Stone said:


> Ferrous sulphate. Turns organic materials (bark etc.) dark brown/black.



Yes it should, while ferric usually makes everything red/orange

We use both a lot at work for various waste water treatment processes.


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## Stone (May 15, 2012)

Someone told me yesterday that they cut the chunks while still green!. If thats the case, no wonder people are having so much trouble with it. All the more reason to soak till it sinks as paphman does and then detoxify by adding your whathaveyous etc, AND ageing. I'm trying this and will see if it works.


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## Paphman910 (May 15, 2012)

Ozpaph said:


> Superb root system. What are your mix proportions?



25% chc, 25% lava rock,25% perlite,15% moss, crushed coral, dolomite lime, and a bit of charcoal.

I keep night temperature at 20C for Paph stonei year round.


Paphman910


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## orchids3 (May 18, 2012)

*Chc*

CHC was my potting material of choice for a while but gave up on it here in damp and hot Florida. A friend of mine who happoned to be a Chemistry teacher at MIT pointed out that there is not a chemical reaction which will remove NaCl (Salt) from any organic material and leave it intact. Soaking and leaching is the best way. I was using Epsom salts like every one else. It didnt make any differance when I stopped using the Epsom salts. 
My potting material now consists of Stalite gravel, Diatomite grit, Dolomite lime and seashell grit. Paphs and Phrags are doing fine (I have around a 100). Cymbidiums (around 2000)are also doing great. Will not change until I see good reason to do so. 
Lime - great for cymbidiums - because it acts a buffer to stop acid swing during periods of heavy rain, is also being tried with Paphs and Phrags but am a little hesitant to get aggressive with its use until the pH levels are studied more in the greenhouse where well water is in use.
Think pH monitoring is important with any potting material and found a drop in pH as CHC rotted. That might be a good indicator of when repotting is due if CHC is used.


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