# Semi hydroponics



## Stone (Aug 9, 2012)

To all the s/h specialists..A few questions please??
I think I understand the basics ( stick the plant in a bunch of stones) but how do you water?
Do you need a water reservoir?
How do you judge the right time to water?
Do you need special pots?
Do you feed more often than with ''convetional mixes''
Do you use larger than normal pots?
Do barbata types do as well as brachy types?
Do you use other media (water retaining or water repelling) to manage water?
Do you ever let the media dry out?
Do you alter the size of the medium particles?
What's the best performing media?

Ahhh......that'll do for now

Thanks in advance.
Mike.


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## Rick (Aug 9, 2012)

Ray is the best to answer these questions, but I'll exercise what I've learned over the years.

1) Semi hydro uses a pot with a reservoir so that there is a small amount of water in the pot at all times. With a 4-6 inch pot there is usually about a 1/2 inch to full inch reservoir at the bottom.

2) as per "special" pots, you need one that is without drain holes, except for overflow holes to let water out at the reservoir depth. I accomplish the same thing by place pots in a pan or shallow bowl and keep the bowl filled to about 1 inch for 6" or large pots.

3) Since you have a constant source of water (and nutrients) the feed rate is much lower than a normal weekly rate. Maybe 1/4 a weekly rate. But Ray will correct me if I didn't remember correctly on this.

4) Pots/reservoirs are flushed out periodically. I've heard as often as once a week, but some may go longer. My big plants (pretty much all phrags and no paphs anymore) actually drain the reservoir faster than once a week during the summer if I don't keep topping up or periodically flushing.

5) Generally the media is fairly large clay pellets like hydroton balls. Some may use ceramic rings, but usually the media I see in use is some type of baked clay or ceramic product that still has some wicking capacity. Particle size is around 1/4 to 1/2 inch diameter.

6) I've used SH with a few barbata types and P.tigrrnum. Some one from Canada posted an awesome belatulum in SH. I saw an awesome award winning Cattleya schileriana grown SH. The owner said he switched all his orchids to SH and was never happier with the results. Otherwise most of my SH experience is with Phrags. I really don't think there's much of a limit to what you can grow SH.

Actually now that I've typed all this, I bet Ray has a fantastic tutorial on his First Rays website. http://www.firstrays.com/hydro.htm


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## Rick (Aug 9, 2012)

When SH works it works great, and folk swear by it. Some folks have had dismal failures. Parts of the SH story are actually part of my logic base for the K lite story.

For instance we go on and on about the danger of overwatering potted orchids in organic media, because it causes root rot. But SH plants have continuous pot water, and when well grown there a lots of roots continually submerged (that don't rot).

So why is soggy organic media dangerous to orchid roots while soggy inorganic media is OK? I think this goes back to your question/thread about root growth after repotting.


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## Stone (Aug 9, 2012)

Thanks Rick.
Do you really need a reservoir? can you just water more often?
Can I just use a pot with a saucer of water under it?


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## Stone (Aug 9, 2012)

Ray, I just read your site. It answered most of my questions. The product we get here is made in Germany and looks identical to PrimeAgra. Could it be the same thing under a different name? (Burger King is called Hungry Jacks here. Not that I eat the sh*t)
What about diatomite?


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## Rick (Aug 9, 2012)

Stone said:


> Thans Rick.
> Do you really need a reservoir? can you just water more often?
> Can I just use a pot with a saucer of water under it?



It's really not SH without standing water of some kind. I don't think it makes a difference if you set a pot in a 1" deep saucer, or a closed pot with overflow holes to leave an internal standing puddle.

Without the standing water the clay will have nothing to wick up and will dry very fast compared to the more absorbent organic media. Then you'll probably have to water every day. Now you're talking close to what I did with the basket mounting, except I've got about a 50/50 mix of large gravel and moss supported in a basket. I water a lot, but at least the moss holds enough moisture to go 2-3 days between waterings.

At this point you are just about talking about another version of plain old mounting. 

I have some vandas in broken clay pots with no media at all. That's about the same thing as a basket or pot of clay balls with no standing water attached.


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## Tom499 (Aug 10, 2012)

I grow my nearly all my orchids in S/H. Most have a continuous reservoir, but I find my Cattleya are happier if I let their reservoir dry out for a day or two, before reflooding their pots.


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## biothanasis (Aug 10, 2012)

Standing a pot in a saucer with water or using a pot with a reservoir does the same thing actually, so whichever you choose depends on what you have available and what is easier to do. However it might be a bit more dangerous to use one big saucer for many plants, but it would be easier to fill with water....

I think that for s/h mainly porous materials are used, such as leca, the grade of which should be anough so that air can pass through and ventilate the roots. I have used leca to fill the reservoire and then sphagnum to wrap the roots. It has worked ok for some pahps I have, but I water only when I see that the sphagnum is getting dry... Roots are active, but I haven;t seen any new roots forming.

Quite frequent change of water is critical I think, but it is largely dependent on what species you have or type of plants, their demand in water etc. 

Additionally, depending on your conditions, water could dry much faster compared to others (e.g. 1 hour after watering), so you should do some checks before using good plants in s/h. Perhaps a misting system could provide much desired results.

As for pots, you could use anything plastic or of other material "cups", punch holes in 3-4cm from the bottom and place the plants in using the potting material u see fit.

Good luck with whatever you do


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## bullsie (Aug 10, 2012)

Tom499 said:


> I grow my nearly all my orchids in S/H. Most have a continuous reservoir, but I find my Cattleya are happier if I let their reservoir dry out for a day or two, before reflooding their pots.



I have the majority of my Cattleyas in s/h and agree with Tom, they do need a dry moment between watering. All of my Phrags are grown s/h. 

But a reminder here is that all leca is not created equal. You will have to adjust culture with them. For instance some are wash and use while others need a soak and treatment. Some wick water more than others. It's not a one rule for all but once you get the 'hang' of it its a great medium.

And everything Rick said!


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## Ray (Aug 10, 2012)

First let me say the "semi-hydroponics" does not fully define orchid culture. It is merely an alternate way to provide water and nutrition. An individual's success or failure can be a result of their other cultural parameters and/or watering habits.

Without a reservoir, it's just traditional culture with an inorganic medium.

Bullsie's comment about not all LECAs being equal is correct, but there is enough variation among them, that you're bound to find one that fits for you. Then there is the fact that a brand that is particularly good at wicking, for example, has no benefit if your RH is high, as the slower wicking rate of another brand may still be able to keep up with evaporation.

I have some plants in diatomite, but I had to use REALLY coarse stuff, and the lighter color seems to really favor algae growth, which can clog things up.

Watering is best done by filling the pot rapidly to the top and letting it drain, (and NEVER just "top up" the reservoir). That flushes the pot at every watering (hence no need for doing so otherwise), saturates the medium, and refreshes the chemistry of the reservoir.

Most failures come about from three general factors:

1) The plant was unhealthy to start with. Repotting is always stressful to some degree. Going into a drastically-different root environment is exceptionally so (most of the time). A weak plant may not take to it.

2) Repotting at the wrong time. Changing in root environment means the current roots won't function as well, so new roots are necessary in the vast majority of cases. If the plants are just beginning to grow new roots, those tailor themselves to the environment, and away it goes. if no new roots are forming, the old ones may fail before new ones take over, and it's "bye-bye".

Paphs are surprisingly good about tolerating a move into S/H pretty much at any time, in my experience. Plants with pseudobulbs are the pickiest.

3) "The rest" of your conditions don't fit well with S/H. The best example is a windowsill-grown phal in a northern climate. Fuel is expensive, so we turn the thermostat down at night. The air is very dry, to the evaporation from the open, airy medium results in sufficient cooling that, when coupled with the lowered thermostat, "pushes" to roots colder than they like (phals are mostly "hot" growers; our moderate temperatures are tolerated), so the die and rot.


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