If you were going to have a problem I would expect it to be the unsoaked CHC possibly having excess salinity than some kind of fungus. That said, I have on one occasion used CHC without soaking and had no problems. It could be that my particular source (Cal-West) sells pre-soaked CHC. Perhaps yours did also. I wouldn't expect it to take long for problems to show, in other words I think you dodged that particular bullet. Green spots are more likely to be algae than fungus. Harmless. CHC is by its nature very 'webby' I am not sure how you can tell that there is something foreign in it. How lucky for you that you have an orchid retailer to bounce questions off. My advice: don't second guess them. If they are wrong then you can take the high road guilt free. Relax! Winter is coming, you will have problems enough without adding more. Do you have lights? Just checking.

H

I have to agree with Howard, your description does not sound like salt damage to me, which would ordinarily be your greatest risk with a change to CHC. I purchased a large bale of supposedly triple washed CHC, washed it again and soaked with MgSo4 and rinsed again, when I used the first batch with one very salt intolerant plant (My Bad) I was promptly punished with browning leaf tips. Emergency un-potting quickly followed, then a trip back to the rain barrel & when that ran out to the R/O water dispenser at Wal-Mart several soaks and rinses in R/O and rain water straight from the heavens, not off a roof, and I finally have usable CHC. Now all my re-potted plants are happy when re-potted into my prepared in-house CHC mix.

Fortunately I only had mixed a small batch of CHC media and had potted up just a couple of plants. My Paph was the canary in the coal mine so to speak, and it saved me from a lot of other plants suffering slowly until I might have figured it out.

CHC is working very nicely for me now, and I have not seen the problem you are describing with my mix. You may already be familiar with this link, but if not it gives some very specific thoughts on CHC as a potting media including some cautions and how best to eliminate the salt issue.

Based on my experience I would be reluctant to use a pre-packaged CHC based mix without being related to the mixer/vendor, or multiple soaks and rinses & possibly both.

Richard

Here is a link that might be useful: Using CHC as potting material

The green spots are mold, possibly a species of Penicillium (yep, that kind of penicillin). The webbing is also fungal. Sap in the husk aids fungal colonization and initial decay. The problem is less in ultra well soaked, and then well dried chips. It is not anything to worry about. Those are not types of fungus that will harm your plants (you won't see those species).

Douse the pots with any fungicide you generally use on your plants and the problem will be reduced.

I've had that happen also. It never seemed to affect the plants. I notice it most in plastic pots and I increase the air flow around those plants and let the chips dry well. I have a few which develop the fungus shortly after watering. It bothered me also, but being lazy, left well enough alone. The plants seem fine and it is over a year.

Jane

After 3 weeks it seems like the "fungus" nearly gone from each pot. I watered my plants as usual and now I found another concern. Some of the plants' leaves turning yellow. Is this the salt damage from the CHC? What should I do now?

I doubt it would have taken three weeks for salt damage to show up in the leaves. What is watering 'as usual'. Remember you changed medium to one that is more water retentive so 'as usual' could be 'too much'? But as I often say, 'overwatering' cannot happen in the presence of good lighting. To make it to the short list of orchid media a bark or moss or expanded clay has to have one important property: the ability to hold a certain amount of air in the mix regardless of the amount of water present. That includes sphag. Within seconds of being watered the mix sheds most of the water that flooded the pot and only holds what its design mandates. Materials like bark hold less water and more air and materials like sphag hold more water and less air by ratio but ALL hold an adequate amount of air for plant respiration. If the product cannot do it it doesn't get to be an orchid medium. Period. CHC is somewhere between bark and sphag but leans towards being wetter but holds a phenomenal amount of air for all that moisture holding. Stop blaming your medium. Not you, specifically, anyone who is questioning I mean. It only leads to fruitless searches for the perfect material. There is none, all can do the job. Obviously you wouldn't use a luxury sedan to help your friend move across town, but you could. You might not want to use sphag to pot up a Catt, but you could. Conditions, conditions, conditions, if the orchid is ailing its living conditions are somehow sub-optimal.

H

Hi, Howard. Thanks for your feedback. What I meant by watering them as usual was, I watered them as I thought needed. I noticed that the CHC retained more water than the bark, so I waited until the chips mostly dried up before I watered again. I normally let the water drained and the rocks that I put in the bottom of the pots really helps with the drainage. I mixed the CHC with pumice when I repotted, so I thought it would balance the media. I'm very careful not to over water them (I "killed" a phal by over watered it when I first started a couple years ago, so I think I learned my lesson and try to go easy with the watering :)

In the past few weeks the weather here had been inconsistent, some days were really sunny and warm in the 70s, then it got really cool around 55 to 60. Last week had been mostly sunny around 65 to 70. I put all my plants indoor along the window facing West, so they get filtered lights during the day. I think they get enough lighting.

I also use Dyna Grow liquid bloom 3-12-6 once every couple weeks when I watered them. Anyway, what do you think?

I have a question. You keep speaking about the CHC coming in a 'brick.' Coconut husk chips come in a bag and are loose chunks of cut up coconut husk, about 1/2" size. Coconut coir comes in a brick and is kind of ground up stuff. Which do you have? They are very different from each other in their use.

The OP is referring to the individual "pieces" of chc, "Bricks or Biquettes". Probably didn't know what to call them.

Clara

Still confusing since the poster clearly uses the term "coconut husk chips" and obviously knows the correct name. When did you last buy 'coconut husk chips' in 'bricks'?

I want to be absolutely positive that is is actually CHC that is being discussed rather than bricks of coir.

Blue, you talk about watering "as I thought needed" and you refer to "I think they get enough lighting". For some of us such 'seat of the pants' flying is unacceptably instinctual. If it works at all is fairly easy to determine but if there are problems then perhaps a move to more objective methods is in order?

Beginning with light, of course, it rarely is enough in North America in the best of places. Indoors is even worse. There simply is no leeway for niceties like 'diffused' or 'dappled' or 'bright shade'. Truth be told, greenhouse growers in the north latitudes use shadecloth to control temperature not to reduce light levels!! So, no, I don't think you have sufficient light unless you are supplementing the dappled west window light with artificial light.

I find that a fixed day of the week (or two) on which to water does less harm than the catch as catch can approach. With CHC, or any medium for that matter, you are not so much waiting for the medium to reach a certain level of dryness before you water again as you are topping up the reservoir of water held in suspension before it runs completely dry. Read that again, everyone. It is key to the overwhelming misconception about watering orchids in North America and similar environs.

In situ when an orchid receives rain the many crannies in the bark of its mount and the overgrowths of moss and the usual high humidity of the sub/tropical environment all conspire to ensure that rarely if ever will the roots see anything approaching total dryness. Not just phals but Catts too. Climb a tree some summer afternoon when it hasn't rained in days. The bark will have a vaguely damp feel to it and this is quite enough. In a tropical environment the bark would be damper still. When you water a pot full of bark the moisture level will still be quite high the next day, the day after that and maybe even the day after that. In nature although still not totally dry, the root environment will admittely be much less soggy than in the pot. Do you really think that waiting seven days to water again gives the roots anything approaching a natural wet/dry cycle? No it doesen't. Nor do you want it to for in North America, especially indoors, we haven't the humidity levels nor the guarantee of daily rainfal or dew, etc. We may as well learn to rely on the inbuilt capacity of the medium to ensure that adequate gas exchange is possible regardless of the amount of moisture present and water as often as neccessary to ensure that the moisture level never falls below zero. But as far as there being a maximum, there is no such thing. Every day watering while wasteful of water should not be harmful if other aspects of culture are exemplary! In North America, however, things are rarely exemplary and a whole regime of countermeasures has arisen to compensate for reduced light, low humidity, temerature extremes, etc. I haven't seen these measures work to my satisfaction so I am trying (and preaching) a method of creating the environment that promotes vigorous growth and development of the orchid like natural conditions do rather than attempting via water starvation regimens to forestall problems brought about by insufficient light and/or insufficient daytime max temp (in winter), low humidity, etc.

Finally, from Blue's language I am pretty certain, like Clara, that s/he is referring to CHC and not coir. And I do believe CHC can be obtained pressed into bricks though mine did come loose in a bag.

H

I agree Howard that that is probably what Blue meant, but since I don't believe in mental telepathy and I haven't heard any answer straight from Blue yet to verify what was meant by bricks, I guess the question still stands. It all boils down to: I, personally, prefer to answer questions specifically directed at me all by myself, rather than have someone else pop up and state what they can read my mind and know what I am thinking. At the very least, if not counterproductive, I find it rude to answer a question asked of someone else, especially when you really don't know 100% what they are actually thinking anyhow. Unless there really is mental telepathy ...

And personally, maybe some do, but I don't see any resemblance whatsoever between CHC and bricks or briquettes. Take a look.

Here is a link that might be useful: CHC

I have bought CHC loose and in brick (compressed) form. You buy your "brick", take the plastic covering off, place brick in a barrow or similar large container and add water.

Cannot add much to all the good stuff written above except to suggest that perhaps pot size is even more important than with other potting materials. Underpotting is a must.

Arthur are you saying you can buy the chunks of coir (CHC) in brick form and you soak them to break into the chunks?

Like cj, I have only seen the chunks offered chunky:>) and coir in brick form which when hydrated is similar to peat.

Brooke

Yes, but i am over here. CHC is readily available (and cheap) and is used as garden mulch. Quality varies a lot. Some bricks have a lot of fines while others are mostly chunks.

Funny how these various materials suddenly get popular and are the ants pants for a while.

For what it is worth I'm using treated pine bark plus chc equal parts and add
about 10% Diatomite chips to that.

Extra moisture provided by CHC component has improved my culture of Onc. Intergenerics.

Just curious, since the article linked mentions that both sphag and CHC hold both water and air at the same time about equally, and better than other media--

has anyone used sphag and CHC mixed, maybe to extend the life of the mix, or whyever?

A couple of years ago I was making my own phal mix out of coir well-rinsed from bricks (Roberts Flower Supply) mixed with diatomite and perlite, and after a few months noticed that some kind of fungus was growing in the mix. It was white webbing with little granules in it. I watered with Physan, thinking that might do away with it. When the second and then the third pot showed the same problem, and I could tell the fungus-infested mix seemed to be repelling water, I unpotted everything and repotted in sphag mixed with diatomite and perlite.

The fungus was like nothing I had ever seen before. As I said in a post at the time, with the perlite and diatomite embedded in it, it was sort of like fruitcake. If you can imagine phal roots growing thru soft whitish fruitcake, that's what I had.

Thanks for everyones responses. I attached the picture of the CHC brick that I bought (yes, I bought them in bricks, not in loose bags).

So, can anyone please share your experience or give suggestions on growing Oncidium and Miltonia, as far as media, lighting, humidity, water frequency and feed?

Howard, would you mind sharing your method of creating the environment that promotes vigorous growth and development of the orchid like natural conditions, for these two species in particular? By the way, I don't mind the preaching.... :)

I live in San Francisco, itÂs not humid here all year around and we are experiencing another dry winter this year. I grow all my orchids indoor, since I live in an apartment building with no balcony or any outdoor arrangements for plants. As I mentioned earlier, I placed all my orchids along the windows facing West, the only place where they can get filtered sunlight during the day.

Blue,
The picture you show is just coconut chips just shrink wrapped into a "brick". It's not really a brick at all, but just a space saving method of packaging. As one post mentioned, sometimes some CHC is not washed and soaked properly. CHC tends to hold a lot of salts. For me, I don't use the stuff. It holds water fine, but seems to have a wicking property and salts do build up on it. I would never mix it with sphagnum because the whole thing will hold too much moisture. As far CHC being a home to mold or fungus, I don't know. Again, for me, I avoid CHC. I grow in long strand sphagnum in clay pots (cattleyas). However, I grow my plants in a greenhouse where they get ample light and air movement. Inadequate light and too much moisture may cause a bloom of fungus. And as one post pointed out, it is true that cattleyas and most epiphytes are never completely dry. Each afternoon, there is usually a good shower to wet the plant roots. The key is good air movement around the plants. Stagnant air will provide the an environment for mold and fugus to grow.