I ran across this unique mist controller:
http://www.phytotronics.com/new.htm#leaf

Has anyone had any experience with this method of controlling misters?

The hort department greenhouse at the community college of the county I live
in has one installed on their misting bench. The instructor seemed quite
taken with it. I think it is meant for a localized heavy misting area, like
for rotting cuttings. Any use in an orchid greenhouse should be careful to
avoid constant wetting and rewetting of the plant's leaves. On the cutting
bench its use was accompanied by a lot of preventative fungicide and
bactericide applications.

Get the catalog from Dripworks. It has lots of misting equipment, timers,
values, etc...
http://www.dripworksusa.com

A l


"Larry Dighera" wrote in message
...

I ran across this unique mist controller:
http://www.phytotronics.com/new.htm#leaf

Has anyone had any experience with this method of controlling misters?

It is intended, as Al says, for seedlings of terrestrial plants that must be
kept constantly damp.

I have a 110V version (From Griffith GH Supply) and used it as a way to
avoid misting if the "sail" has not dried out since the last time. What I
mean is, rather than misting when the sail gets light and lifts (as
designed), I only get misting when my timer and it coincide to apply power
to the solenoid valve.

--

Ray Barkalow First Rays Orchids
http://www.firstrays.com
Secure Online Ordering & Lots of Free Info!


"Larry Dighera" wrote in message
...

I ran across this unique mist controller:
http://www.phytotronics.com/new.htm#leaf

Has anyone had any experience with this method of controlling misters?

On Mon, 16 Jun 2003 18:51:47 -0400, "Ray @ First Rays Orchids"
wrote in Message-Id:
:

It is intended, as Al says, for seedlings of terrestrial plants that must be
kept constantly damp.

I have a 110V version (From Griffith GH Supply) and used it as a way to
avoid misting if the "sail" has not dried out since the last time. What I
mean is, rather than misting when the sail gets light and lifts (as
designed), I only get misting when my timer and it coincide to apply power
to the solenoid valve.

Hmm... That's an interesting way of controlling misting. I suppose
you designed the circuit's operation based on empirical observation
and your intended results from misting.

Without actually trying it, I would have thought that a humidistat and
"leaf switch" would have been more appropriate than a timer. On the
other hand, I can see where all three in series might be useful. I
suppose it depends if your intent in misting to irrigate or maintain
humidity.

"Larry Dighera" wrote in message
.. .

I ran across this unique mist controller:
http://www.phytotronics.com/new.htm#leaf

Has anyone had any experience with this method of controlling misters?


On Mon, 16 Jun 2003 18:34:49 -0400, "Al" wrote in
Message-Id: :

The hort department greenhouse at the community college of the county I live
in has one installed on their misting bench. The instructor seemed quite
taken with it. I think it is meant for a localized heavy misting area, like
for rotting cuttings.

LOL. Was that Freudian, or intentional?

Any use in an orchid greenhouse should be careful to
avoid constant wetting and rewetting of the plant's leaves.

I can see the "leaf switch" used a safety device to override scheduled
(via timer or humidistat) misting when the previous misting hasn't yet
evaporated.

On the cutting
bench its use was accompanied by a lot of preventative fungicide and
bactericide applications.

I get it; reliance on the "leaf switch" alone will likely lead to over
damp conditions.

Get the catalog from Dripworks. It has lots of misting equipment, timers,
values, etc...
http://www.dripworksusa.com

A l


Many thanks for the link. I'll check it out.

You seem pretty familiar with controls. You wouldn't be aware of any
water sensors for use in controlling irrigation would you?

Thank you for your informative follow up.

I use a timer and humidistat in series...

"Larry Dighera" wrote in message
...
On Mon, 16 Jun 2003 18:51:47 -0400, "Ray @ First Rays Orchids"
wrote in Message-Id:
:

It is intended, as Al says, for seedlings of terrestrial plants that must
be
kept constantly damp.

I have a 110V version (From Griffith GH Supply) and used it as a way to
avoid misting if the "sail" has not dried out since the last time. What
I
mean is, rather than misting when the sail gets light and lifts (as
designed), I only get misting when my timer and it coincide to apply
power
to the solenoid valve.

Hmm... That's an interesting way of controlling misting. I suppose
you designed the circuit's operation based on empirical observation
and your intended results from misting.

Without actually trying it, I would have thought that a humidistat and
"leaf switch" would have been more appropriate than a timer. On the
other hand, I can see where all three in series might be useful. I
suppose it depends if your intent in misting to irrigate or maintain
humidity.

The problem with not using a timer is that you might end up misting in the
evening or at night when drying rate will be at a minimum, meaning that
moisture could sit on the plants, in the crown all night when it's cool -
rot city.

--

Ray Barkalow First Rays Orchids
http://www.firstrays.com
Secure Online Ordering & Lots of Free Info!


"Larry Dighera" wrote in message
...
On Mon, 16 Jun 2003 18:51:47 -0400, "Ray @ First Rays Orchids"
wrote in Message-Id:
:

It is intended, as Al says, for seedlings of terrestrial plants that must
be
kept constantly damp.

I have a 110V version (From Griffith GH Supply) and used it as a way to
avoid misting if the "sail" has not dried out since the last time. What
I
mean is, rather than misting when the sail gets light and lifts (as
designed), I only get misting when my timer and it coincide to apply
power
to the solenoid valve.

Hmm... That's an interesting way of controlling misting. I suppose
you designed the circuit's operation based on empirical observation
and your intended results from misting.

Without actually trying it, I would have thought that a humidistat and
"leaf switch" would have been more appropriate than a timer. On the
other hand, I can see where all three in series might be useful. I
suppose it depends if your intent in misting to irrigate or maintain
humidity.

I have my misters set under the benches, pointing down. This keeps the
humidity up and the leaves dry. I mist everything with R.O. water first
thing in the morning to keep things dust free. I live in a pretty dry area
(Sacramento) so excess humidity is not a problem. Quite the contrary! It
sure makes the evaporative coolers work well. It was 100 degrees today and
the houses topped out at 81. ;-)
"Larry Dighera" wrote in message
...
On Mon, 16 Jun 2003 18:51:47 -0400, "Ray @ First Rays Orchids"
wrote in Message-Id:
:

It is intended, as Al says, for seedlings of terrestrial plants that must
be
kept constantly damp.

I have a 110V version (From Griffith GH Supply) and used it as a way to
avoid misting if the "sail" has not dried out since the last time. What
I
mean is, rather than misting when the sail gets light and lifts (as
designed), I only get misting when my timer and it coincide to apply
power
to the solenoid valve.

Hmm... That's an interesting way of controlling misting. I suppose
you designed the circuit's operation based on empirical observation
and your intended results from misting.

Without actually trying it, I would have thought that a humidistat and
"leaf switch" would have been more appropriate than a timer. On the
other hand, I can see where all three in series might be useful. I
suppose it depends if your intent in misting to irrigate or maintain
humidity.

Now there's a place that the leaf switch device might be OK by itself -
under the benches. Misting occurs whenever it gets too dry - which is
adjustable, by the way.

The biggest problem I found with their use in an orchid house is air
movement. My fans move the thing way too easily.

--

Ray Barkalow First Rays Orchids
http://www.firstrays.com
Secure Online Ordering & Lots of Free Info!


"Dave Lockwood" wrote in message
news:V5yHa.5924$hz1.9518@sccrnsc01...
I have my misters set under the benches, pointing down. This keeps the
humidity up and the leaves dry. I mist everything with R.O. water first
thing in the morning to keep things dust free. I live in a pretty dry
area
(Sacramento) so excess humidity is not a problem. Quite the contrary! It
sure makes the evaporative coolers work well. It was 100 degrees today
and
the houses topped out at 81. ;-)
"Larry Dighera" wrote in message
...
On Mon, 16 Jun 2003 18:51:47 -0400, "Ray @ First Rays Orchids"
wrote in Message-Id:
:

It is intended, as Al says, for seedlings of terrestrial plants that
must
be
kept constantly damp.

I have a 110V version (From Griffith GH Supply) and used it as a way to
avoid misting if the "sail" has not dried out since the last time.
What
I
mean is, rather than misting when the sail gets light and lifts (as
designed), I only get misting when my timer and it coincide to apply
power
to the solenoid valve.

Hmm... That's an interesting way of controlling misting. I suppose
you designed the circuit's operation based on empirical observation
and your intended results from misting.

Without actually trying it, I would have thought that a humidistat and
"leaf switch" would have been more appropriate than a timer. On the
other hand, I can see where all three in series might be useful. I
suppose it depends if your intent in misting to irrigate or maintain
humidity.

Ray Barkalow First Rays Orchids
http://www.firstrays.com
Secure Online Ordering & Lots of Free Info!


"Larry Dighera" wrote in message
.. .
On Mon, 16 Jun 2003 18:51:47 -0400, "Ray @ First Rays Orchids"
wrote in Message-Id:
:

It is intended, as Al says, for seedlings of terrestrial plants that must
be
kept constantly damp.

I have a 110V version (From Griffith GH Supply) and used it as a way to
avoid misting if the "sail" has not dried out since the last time. What
I
mean is, rather than misting when the sail gets light and lifts (as
designed), I only get misting when my timer and it coincide to apply
power
to the solenoid valve.

Hmm... That's an interesting way of controlling misting. I suppose
you designed the circuit's operation based on empirical observation
and your intended results from misting.

Without actually trying it, I would have thought that a humidistat and
"leaf switch" would have been more appropriate than a timer. On the
other hand, I can see where all three in series might be useful. I
suppose it depends if your intent in misting to irrigate or maintain
humidity.

On Tue, 17 Jun 2003 00:46:46 -0400, "Ray @ First Rays Orchids"
wrote in Message-Id:
:

The problem with not using a timer is that you might end up misting in the
evening or at night when drying rate will be at a minimum, meaning that
moisture could sit on the plants, in the crown all night when it's cool -
rot city.


Yes. That's true.

It wouldn't be prudent to rely on the humidistat to prevent that even
though humidity rises with the drop in night temperatures.

The college greenhouse I used to run back in the late 80's was a
very similar model; it tended to keep things too wet. However, if you take
a small piece of paper towel, and put it over the stainless steel mesh
(and adjust the counterbalance on the other end of the leaf), it absorbs
more water and takes longer to dry out. It still keeps the humidity up
while not soaking everything.

For orchid use, you'd have to put a timer interlock on there so it
didn't go off at night, as someone else noted.

-AJHicks
Chandler, AZ

On 17 Jun 2003 09:51:25 -0600, (Aaron Hicks) wrote
in Message-Id: :

The college greenhouse I used to run back in the late 80's was a
very similar model; it tended to keep things too wet. However, if you take
a small piece of paper towel, and put it over the stainless steel mesh
(and adjust the counterbalance on the other end of the leaf), it absorbs
more water and takes longer to dry out. It still keeps the humidity up
while not soaking everything.

There's a creative solution. Thanks for the input.

For orchid use, you'd have to put a timer interlock on there so it
didn't go off at night, as someone else noted.

-AJHicks
Chandler, AZ


If low humidity prevailed even at night, would you consider running
the misting system without a timer (with perhaps a humidistat in
series with the leaf switch)? Or is it unrealistic to encounter low
humidity at night? Being located in Arizona, you are probably
knowledgeable about such things.

Larry Dighera wrote:
On 17 Jun 2003 09:51:25 -0600, (Aaron Hicks) wrote
in Message-Id: :
For orchid use, you'd have to put a timer interlock on there so it
didn't go off at night, as someone else noted.

-AJHicks
Chandler, AZ



If low humidity prevailed even at night, would you consider running
the misting system without a timer (with perhaps a humidistat in
series with the leaf switch)? Or is it unrealistic to encounter low
humidity at night? Being located in Arizona, you are probably
knowledgeable about such things.


This is what I was wondering as well. We frequently get blasted by
Santa Ana winds at night. 40-50 mph wind and the humidity drops to
effectively zero. I can get them out of the wind, but it's hard to
escape the bone dry air. Why would I want to avoid misting just because
it's dark?

garyr

If low humidity prevailed even at night, would you consider running
the misting system without a timer (with perhaps a humidistat in
series with the leaf switch)? Or is it unrealistic to encounter low
humidity at night? Being located in Arizona, you are probably
knowledgeable about such things.

Depends upon where your misters are going, as well as the size of
the mist. If your misters would be delivering water straight to the plants
(i.e., where it might accumulate in the crowns or on the leaves or other
locations vulnerable to rot), then you're just asking for trouble. Many
orchids are CAM plants, which means the stomata open at night. When the
stomata are open, the fungi can get in and rot the plants. My mycology
prof did some work with one of the big chip fabs, which made it possible
to produce little slabs of metal with stoma-sized holes in them. The slabs
were also "striped" in the same way that cells run parallel to the length
of the leaf.

When the fungal spores germinated, they followed the parallel
lines, and when they found a hole, BLOOP! Right down into the hole. It was
incredible. Beautiful scanning electron micrograph images of it all. My
only remaining question is why they can't do the same when the stoma are
only partially open, since stoma never really close tightly. You'd think
the mycelia would be able to snake down in there.

ANYWAY. I suspect this is one of the reasons why orchid rule
number 12 (or whatever) is to water and mist during the day. Thanks to the
unusual physiology of orchids, water on the leaves at night is just asking
for trouble. Further, I have no proof, but a sneaking suspicion that the
fertilizers we add to solution encourage fungal growth. Whether these
fungi are pathogenic or not is, of course, an unanswered question. Urea
(as found in Peter's and some other fertilizers) is particularly suspect.

This rule is, I am sure, broken by a number of people who will
report not only complete success, but hundreds of FCC's, CCM's, CBR's,
FBI's, NSA's, and M-O-U-S-E's, despite watering them at night. Until such
time that one is elevated to Diety of Much Orchidaceous Wisdom, keep it
simple and don't water at night, and don't mist such that water gets on
the leaves when the sun isn't up.

Depending upon how your system is run, you may find that humidity
increases after dark (as it gets cooler, water holds less moisture, so
relative humidity goes up without adding any moisture), or decreases (if
your misters are off, and your greenhouse exchanges air with the outside
in significant quantities). Fortunately for us, orchid growers are often
willing to tweak or tinker to achieve desired results.

Cheers,

-AJHicks
Chandler, AZ