Re: greenhouse-tomatoes: Want to automatically trigger irrigation cycles

["Dr.-Ficus_Hydroponicus" <Dr.Ficus_Hydroponicus@mauipacifica.com>]

greenhouse-tomatoes - an email list for growers of greenhouse tomatoes.
Sent by "Dr.-Ficus_Hydroponicus" <Dr.Ficus_Hydroponicus@mauipacifica.com>.
-

Well Michael:

I really don't resent, as a fellow academician, your references to
defibrillation and the potential for the  ensuing possibility of an induced
catatonic state.  I would hope however that, at least, you have had a few
pre-plant medical courses as part of your vita curricula.  I welcome you
into the limited field of arcane wit and pseudo science.  Please watch your
back for rampant flux.

Aloha

Dr. Ficus Hydroponicus


----- Original Message -----
From: "Michael Pierce" <michael@mrhydro.com>
To: <greenhouse-tomatoes@Lists.MsState.Edu>
Sent: Thursday, June 10, 2004 6:01 PM
Subject: RE: greenhouse-tomatoes: Want to automatically trigger irrigation
cycles


> greenhouse-tomatoes - an email list for growers of greenhouse tomatoes.
> Sent by "Michael Pierce" <michael@mrhydro.com>.
> -
>
> I'm going to have to chime in here! DO you want to grow tomatoes or go
into
> computer programming?
>
> First of all, good for you; you have a system that you have invested in so
> as long as it works to a good degree, keep it. It does sound like it needs
a
> little help.
>
> If I understand, your timers are feeding 4 times per day for each timer (a
> total of 8 times a day for both timers). If this is correct, you are
feeding
> 6 minutes of water 4 times a day for one timer. THIS IS NOT GOOD!! On top
of
> that, you are watering out of a PVC pipe reduced to a spaghetti tube. I
> don't have my flow calculator in front of me but running water out of a
> spaghetti tube for 6 minutes (without a pressure compensated dripper) is
> going to dump a bunch of water. All of this water must be running to
waste.
> You need more control of the flow even if you don't add drippers.
>
> If you have the two timers wired to water the whole range 8 times a day
for
> 6 minutes each feeding, THIS IS NOT GOOD!!
>
> If the sun comes up at 6:00 AM and you begin to water at 8:00 AM then you
> will only water until 4:00 PM (that is 8 feedings). You still have 3.5
hours
> of light left in the day. I'm not sure where you are and I'm not sure
about
> saw dust but I would not stop watering at 4:00 PM in Houston, Tx.
>
> I'll go back to something much simpler than diodes, relays, and other
> electronic wizardry. What do you mean by "the plants needs"? I say get a
> controller that waters what you want; something per second per minute.
This
> will allow you to water so many seconds every few minutes for any duration
> through out the day or night. (BTW - you should not have to water at
night!)
>
>
> I'm going to see if I can get some saw dust to see what water holding
> properties it has. My first reaction is to ditch that stuff and go with
> perlite.
>
> As a general rule, water cycle timers and individual thermostats will not
> suffice for commercial tomato greenhouses. They are very limiting and do
not
> allow for the flexibility that is needed to manage proper environmental
> needs.
>
> BTW - flushing with non-pH corrected water is going to exacerbate your
> wilting problem because it's going to knock the pH to hell and back and
then
> your anions are going to be defibrillating with the cations.
>
> In other words, there will be a fluctuation in the eddy currents that will
> incapacitate the flux capacitor!
>
> Michael Pierce
> M & R Hydroponic Farms
>
>
> -----Original Message-----
> From: owner-greenhouse-tomatoes@Lists.MsState.Edu
> [mailto:owner-greenhouse-tomatoes@Lists.MsState.Edu] On Behalf Of Eng,
Doug
> MSER:EX
> Sent: Thursday, June 10, 2004 11:59 AM
> To: 'greenhouse-tomatoes@Lists.MsState.Edu'
> Subject: RE: greenhouse-tomatoes: Want to automatically trigger irrigation
> cycles
>
> greenhouse-tomatoes - an email list for growers of greenhouse tomatoes.
> Sent by "Eng, Doug MSER:EX" <Doug.Eng@gems3.gov.bc.ca>.
> -
>
> Hello,
>
> Thank you for your feedback.  The autopot system is very interesting
however
> the
> switchover for me would be too expensive because I would need enough for
> 4000 plants.
> Also, I have a system in place already. The lysimeter sounds like what I
am
> after.
>
> Here is bit of info on how I am doing irrigation. I have about 4000 tomato
> plants in sawdust
> filled plastic bags.  2 per bag. The irrigation is delivered by a 115v
pump
> through 2" pvc
> pipe. The pipe sizes decrease until it eventually arrives at the bag as a
> pair of .045 speggetti
> feeding tubes.  I have a pair of timers (intermatic electronic - max 4
> cycles) that cycle on/off
> the irrigation pump. At this time of year each timer is programmed for 4
> cycles ( 6 minutes = 1 feeding)
> and together they feed 8 times a day.  On a cloudy day I disable one of
the
> timers to get 4 feedings.
>
> This crude setup usually works okay. I try to give enough feedings to see
> drainage on a sunny day.
> Unfortunately as the plant's needs increased, I did not increase the
> feedings.  The result was
> the leachate stopped happening and thus salt builtup in the bag.  The top
1
> foot of the plant looks
> wilted and the leaves are drying out.  In desparation, I am going around
> with a garden hose and
> manually flushing each bag with plain water in hopes of correcting this
> condition.
>
> I could have avoided all this if I had implemented something like a
> lysimeter.
>
> Doug Eng,
>
>