How often flush the container
 

I'M new to the forum and rather new to S/H. Started about 1 month ago to convert some plants of my small collection. I care for them with Rain Mix and Kelpak. Til now all is fine and they are still happy.

Some questions:

I was astonished how fast the water evaporates or is used by the plants, I have to refill the reservoir every 2 to 3 days. How often do you flush the reservoir?

Two holes in the container, am I right that the second hole is just for safety in case one hole is blocked by leca?

It should be done at every watering.

Fill the pot quickly to the top and let it drain.

Yeah, that’s pretty much the reason for 2 x 6mm holes versus one, larger one.

Thanks for your quick answer, Ray.
But isn't it enough to refill every 2 days and flush maybe after every 2 weeks?

In my opinion, no.

As the water evaporates and is replenished from the reservoir, minerals and plant wastes concentrate in the LECA. Once they are absorbed and the LECA starts to dry, the deposits are very difficult to redissolve and remove. By flooding the pot with dilute nutrient solution at every watering you flush then saturate the medium, and refresh the chemistry of the reservoir.

When S/H orchid culture was first introduced, some folks routinely topped-up the reservoir, flushing only about once a month. Within a year or two they started noticing a general decline in their plants.

Others did the "flood-and-let-drain" technique at every watering and had no such issues.

Ok thanks a lot.

Hi Peter, and welcome to Orchid Board. Ray is a wealth of knowledge regarding semi-hydro growing. Following his advice is how I learned to grow in SH, and I now use that method almost exclusively.

A couple of things I do differently... I no longer put two holes in my containers. Ray developed the two hole system because he had an automatic watering system, and would be gone traveling quite often. If the one hole got plugged and didn't drain, problem. I drill a lot of glass for containers, and don't have my watering system automated, and find two holes unnecessary.

I use RO water, and flush a minimum of once a week. I fertilize weakly when I flush. About once during the middle of that week, I use plain RO water, no fertilizer, and flush smaller pots. Large pots (half gallon size or bigger) I only fill a couple of inches past the reservoir line.

The size of the pot, and the type of orchid you're putting in the pot, also dictates how much reservoir you have. Perhaps you don't have enough reservoir for some of them? I don't know, just asking.

Also, in lower humidity, there are ways to decrease evaporation. Using plastic over a portion of the top, covering top of LECA with non-porous stones (rocks) or marbles, or decorative glass stones.

That is what I want too, except a few older plants I doubt they could be converted.

With plastic containers two holes are no problem but I'm much to lazy drilling holes into glass. So I'll stick with one hole in my glass containers :biggrin:

Very good information and tips, thank you so much.
I'll definitely try rocks above the LECA and a similar method to flush as you described.
Time will tell, thanks again.

i assume you are asking about the need to flush, but the advantage of the SH method is you CAN flush all the time and the more water, the more action (growth)

i flush (rain water) almost all my SH plants every day and i fertilize daily with super dilute K-Lite

You are right DC, I wanted to know how often I HAVE to flush at least, at a minimum. Until now I have done that once a week and between refilled when it's went to get dry. The refill is always with fertilizer. Cause i can't get K-Lite here in Germany I'm using Rain Mix which is rather similar. Every two weeks I add Kelpak (same as KelpMax) to the solution.

And DC, I’m not convinced flushing daily makes them grow quicker. What’s your rationale for that?

I'm gonna back DC up on that. There are a few factors to consider:

1) Water is the true driving force for growth.

2) If the plant has a regular, plentiful water supply at the root system, it sends hormonal signals to the leaf stomata that "we're not at risk of desiccating if you open, so go ahead and do so", which allows for faster/greater carbon dioxide uptake and carbon capture (AKA "growth").

3) If the plant is watered more frequently, more of the root system absorbs it. Even in an S/H pot, not 100% of the root is in contact with moisture, but if you water a lot, 100% is wetted more often.

4) If that "water" contains a low level of fertilizer, the plant is also taking up more nutrients, similar to the water, above.

Many moons ago, I acquired 300 each of Phalaenopsis Lemforde White Beauty and Oncidium Sharry Baby as very large "seedlings" in flats, and potted them all up in S/H pots. Using eyeballed plant size as a way of splitting each population into two, more-or-less equivalent groups, I then weighed each individual plant and documented that.

One set of 150 of each type was watered with 25 ppm N (MSURO) every second or third day, with the rest of the greenhouse. The other set was watered with the same solution every single day.

At the end of 6 months, the "every day" group was visibly larger than the others, and taken as a whole was just under 20% more mass.

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B727 - Please send me a private message so I can reply with some info.

i am using the act of flushing but it serves two purposes, clearly, to flush the rez and keep the LECA from holding any detritus etc but it also is hydrating the leca.


while it may be VERY negligible, i feel that i make sure the plant is never wanting at all...if i can keep the full SH container at peak hydration then there is no time when the plant is not at peak hydration...
that is my reasoning, is it backed up by science, only Ray's test and my anecdotal experience


it is also always possible that since i LIKE to water, i am inclined to see the benefits of watering?? of course it is


what Ray said...LOL

Do it every day for six months, and then tell me how much you like to water.

Gotcha. So then after that it boils down to how much effort/time one wants to expend. And thank you for the story about the actual testing of the theory. Interesting. I guess at end of day, both survive... one just a bit more lush.

Having said that... what about particular orchids that do like to dry out a bit prior to watering? Or that have a season where they prefer to dry out a bit? Not applicable in that situation?

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LOL... for me, I already know that answer! :rofl:

Well I actually use that as my cutoff for plant purchases, do I want to have to add this to the “take care of” plants. It’s why I steer away from some new genus. I don’t want to accidentally add a new step to my daily routine.

I am of the opinion that - once a plant is fully acclimated to the S/H environment - it doesn't ever have to dry out.

Maybe you need to withhold fertilizer, but water...no.

Having said that, I base that on the plants I have grown that way, and I have not grow everything.

All I want is more orchids, better growth, constant flowers and less time caring for them.

Same here! Just not in that particular order. :biggrin:

I think my wants would be

Constant flowers
More orchids
Less time caring for them
Adequate growth

I personally flush my pots, semi-hydro or not, thoroughly every watering. However, if you wan't to see some more creative adaptations to semi-hydro I recommend checking out "The Orchid Room" youtube channel. The Orchid Room
- YouTube

She mixes different aggregates with LECA depending on species and has some really interesting methods for eliminating the dry top layer among other things. Another thing- she does not heavily flush with every watering and feeds fairly heavily with a pump sprayer wand- just filling the reservoir. She also uses a lot of self watering pots. I believe that she flushes on a schedule. Hard to argue with her results and she is able to water a huge collection fairly easily.

Either way, flushing is probably ideal but you can get good results multiple ways. One caveat here though is that pure or low TDS water is probably a requriement.

Too many people have ultimately failed by just refiling the reservoir. Flushing is essential.

I checked out Orchid Room... can't watch her videos... too long, and I have a short attention span. And for some reason find it really hard to understand what she's saying. Both those are my issues, not hers.

That's quite a sweeping statement, Ray. And I don't think that's what fishmom was saying. I think she was saying this gal doesn't flush every time she waters, but does have a flushing schedule.

I'm just providing information that suggests that flushing in semi-hydro isn't the end all be all. She grows some in self watering buckets where she takes synthetic fibers and strings them through the LECA to improve wicking throughout and to wick from the reservoir.

Here is how she waters the collection; if your attention span is bad feel free to skip through. I just want to show that you can modify semi-hydro and achieve really good results.

Here is her watering video (this will probably trigger Ray)
YouTube

And in my “sweeping statement” I did not say that not doing it at every watering was “wrong”. What I did say was only topping up the reservoir and not flushing will set your plant up for failure.

That is true of setups using fabric wicks, too.

As the solution is wicked upward it carries the dissolved nutrients and plant wastes with it. As the water evaporates from the top, those are deposited as solids. Over time, they will become toxic.

That is true of all in-pot growing, no matter what the medium.

Nobody is arguing that flushing isn't required. Additionally, nobody is arguing that toxic wastes won't build up over time. The discussion is whether you need to flush every watering in semi-hydro and I think that your opinion on it is so dogmatic that it's borderline unhelpful.

I had some dark times a few years ago and had my collection fall under poor care, at times I was simply refilling the reservoir on my semi-hydro plants for months on end. The rest of my plants were severely underwatered. My Rossioglossum grande bloomed and actually thrived under the regimen despite this toxic wastes and salts boogeyman- I never saw black root tips and my growth rate was similar to when I was caring for it under an 'ideal' regimen.

There are other ways to reduce salt buildup or the negative effects. Proper pH, microbial inoculants and use of silicates are some that come to my mind.

Agreed. And I’ve never flushed every time I water. And never had problems. In a perfect world I flush once a week, and top up about halfway through the week. Usually with RO. And I fertiluze wvery week.

That’s the goal of my perfect world. Rarely does it match my reality for more than a couple of weeks. It’s more like flush every ten days to two weeks the half year they’re inside, topping up a couple times in between. My fertilizing is worse.

I went through a couple of dark years a ways back. I just turned on a hose and they got tap water, with high TDS. Except for four or five plants... they got a glug or two from bottled water. Nothing missed a beat.

Granted, in time, especially with my hard water, I got some mineral deposits. Pretty easy to dump out the LECA and plunk back in, refreshing what fell off.

I’ve grown many other plants for years and yes, you have to replace potting soil regardless of whether you use a wick. (for me, wicks are worthless, but more power to those who want to use them.)

I know you didn’t literally say not flushing each time was “wrong” Ray. But you are intimating plants not flushed each time will fail, over time. To me, saying the same... a sweeping statement. I disagree and have the poor regime of flushing to prove it. I believe that’s the dogma thefish is speaking of that’s borderline unhelpful. Culture of orchids isn’t a my way or the highway regardless of the method of growing, including semi-hydro.

That's right WW, I never said flushing had to be done at every watering, but I do believe that it was better to do so. "Intimation" is in the mind of the reader, no? Let me clarify, then:

In my opinion, which is based upon some science, some logic, and lots of observation, it is best to flush an orchid - no matter the culture technique used - at every watering, and preferably with a high-volume, low pressure "rain head" on the hose, as it achieves several things that other watering methods do not:

► It wets the potting medium very thoroughly throughout its volume.

► In doing so, it flushes the medium, removing mineral residues, plant wastes, small media decomposition products and some biofilm.

►It also will maintain it's moist atmosphere longer.

► Such flushing slows the buildup of stuff that can eventually become toxic to the plants.

► If the flushing is done more frequently, before the medium has had a chance to dry, the greater the percentage of residues are removed and the more pristine the medium stays

► It wets the root system more thoroughly, as well, giving the plant more raw materials for growth.

► If that routine flushing is done with dilute nutrient solution, it gets more food, too.

► It draws fresh air through the medium, oxygenating it better than ambient air movement can achieve.

Must a pot be flushed at every watering? No, but we should recognize that there are some negatives associated with not doing so, and the less frequently they are flushed, the more those negatives will rear their ugly heads. Like almost everything in orchid growing, there is a gradient from "that's great" to "avoid it like the plague". My preference is the former; not flushing at all is the latter - you are welcomed to choose your own location on that spectrum.

I thought this thread was called “do you flush every time” and assumed it had to do with toilet use.....

Okay, Ray, I understand what you're saying, but let's go back to the beginning. A new member (and new to SH) asked the question...

You replied that it had to be done each time. And our new member asked:

And you reply with "No," not in your opinion. Then DC says the beauty of SH is you can flush daily if you want.

Then OP says:

So TheFish and I give OP other ideas and ways to go about it. You come back with a simple "flushing is essential," which is back to your original... should flush each time you water. And ignoring the fact others do it differently with no problems. That's how the sweeping statement verbiage from me came to be.

And never giving an opinion that one "might" be able to accomplish the same thing without totally flushing a plant each time in SH. Or that trying something horribly detrimental like using wicking (which I said I don't think works, but so be it for those who choose to do so) and which some folks do, with success.

No, I don't think intimation is always in the eye of the reader. I think sometimes it's in the mind of the writer. And I believe you intimate if flushing isn't done other than on an every time basis, bad things are sooner or later going to eventually happen, and you're playing a craps game or Russian roulette with your orchids. I totally disagree with that statement.

And most folks also can't flush with a high volume, rain shower head, regardless of SH, bark, or rock, each time they water a plant. They either don't have that set-up because they're growing in a house and don't have the capability of using that, and/or have too many orchids growing inside to take them somewhere to do so each time they water.

I KNOW you think flushing each and every time is best. I don't think it's that crucial, at all, to flush each and every time water is added. And it appears our OP, new to SH, is wanting to know what he can get away with without flushing each and every time. Without harm to the plants. Thus, other opinions.

I live in a climate with very low humidity at times (under 10%.) I have grown in S/H in my house, which has humidity around 30%-40% depending on how many canines are here. I also have plants in S/H in my sunroom, which has an evaporative cooler. The humidity there is in the 60% range. I fill each S/H container to the brim (flush) at each watering.

The plants in S/H grow better the more frequently I can water and flush them. I wish I had time to flush daily. I agree it's not a good idea to avoid flushing, instead only topping up the reservoir.

I grow mostly in a sunroom with a concrete floor. I don't mind runoff on the floor. I understand flushing can be a lot of work if the growing area doesn't have a waterproof floor.

If you are looking to water less frequently than is best for S/H, consider learning to grow in long-fiber sphagnum moss. It is possible to stretch watering intervals longer with sphagnum than with other methods. However, growing in sphagnum is very different from growing in other media.

You never soak the moss. You lightly water just the top of the moss. The water evenly diffuses through the moss. It stays lightly moist. When the pot is dry, you water again. Very few orchids use enough water to be happy in sphagnum that gets soaked.

People must keep their plants in sphagnum separate from other plants. It is too easy to overwater the plants in sphagnum.

Thank you for your post WW, that is exactly the answer to my initial question.

@Ray
Don't get me wrong Ray, I appreciate your knowledge and your advice. But your words sound to me that I will send my plants direct to hell if I just refill the reservoir and don't flush at every watering.

Thank you all for this discussion. I think there are some good points especially for S/H newbies.

B727 - my intention was to relate the best way to handle it, not to make you think your plants were doomed if you deviated an iota. Sorry if I failed.

No reason to be sorry. All is clear now :D

I think there is another element at play here which I see often as an outsider to the conversations

Ray gets attacked A LOT by random people who seem to just want to prove that SH doesn’t work or is a fluke. As a result, I see Ray always preaching the IDEAL way to execute the culture. This makes complete sense give that
1) the culture DOES work so stop attacking it,
2) Ray is bound to be, even unconsciously, protecting the SH culture by hoping it is done perfectly so there aren’t more people out there who are complaining and talking Sh1t about SH when they are not even doing it correctly, and
3) There is no tone or inflection on the internet and you simply cannot tell if something is soft as a suggestion or hard like a command...the words can be the same


Cheers all

I agree with most of what you say, DC. Except Ray knows I'm not attacking him personally and not just arguing it doesn't work. Obviously, as I grow almost exclusively SH. I was discussing "absolutes" vs "works" for a newbie (that's you 727) :D which was the info this particular person was seeking.

Yes, I agree Ray vehemently protects SH techniques, as he does get a lot of bashing from folks regarding semi-hydro... giving "absolutes" advice that it doesn't work vs. "absolutes" advice that you must follow some basic format in order for it to work.

And new person B727 gets to see Ray and WaterWitchin carry on with each other... yet another rare siting of the Bill Nye vs WaterWitchin keyboards at play! :rofl:

i want a slap fight emoji!!!

i was not saying you were attacking him WW, just that a lot of randos create accounts to just attack his culture and so i know I would get careful about being very strict with my advice...


jerks, they salt us all

There's a boxing fight emoji... I find it highly unsatisfying...

And yes, DC, I know. You could probably be a mediator when ya get tired of lawyering. ;)

:duh:

I don't know, WW. I started to cry :bua: after your prior post.


:rofl:

Oh Honey!! Just get on over here for a hanky! I think DC’s got a couple of extras other than the one he swoons over Patrick Swayze with!

well, considering how many movies Swayze has to be swooned over....i am running out of hankys

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who knows how to embed a .gif?

https://live.staticflickr.com/65535/...a74061c0_n.jpgSlap fight by J Solo, on Flickr