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Table of Contents:
- 1. Hydroponic management
- 2. Equipment failures
- 3. Here and there
- 4. A few ideas on aquaponics
- 5. For a good mesclun mix...
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1. Hydroponic management
You need to know some details if you are going to advance in this
business. Here are the main ones to consider:
Nutrient problems:
- a. What is the temperature of the solution - daytime and seasonal?
Is there anything in your water which will restrict nutrient
availability to the crops?
- b. How's the pH? Does the range vary too much?
- c. What is the electrical conductivity (EC) of the solution?
- d. How's your water supplier? What is the dissolved solid content
and does it vary to extremes? If you don't know, ask the supplier.
- e. For each crop cycle, do you have different nutrient formulas for
each plant growth stage?
- f. Have you considered how plant growth effects your nutrient
solution, especially a drop in nutrient levels in the supply tank,
change of EC,and even pH?
- g. Have you considered the reasons for changing the nutrient
solution to avoid salt, plant waste buildup and loss of nutrient
strength?
- h. Do you have pathogens from sick plants or from contaminated
water?
Most problems of poor plant growth can be traced to one or more of
the above. Avoid extremes and remember in hydroponics you must be
on the lookout for anything which can go wrong with the root system
of your plants.
Let's look at your water supply:
If you live on a city water main, you can call the proper agency
and get a copy of the most recent "readout" of what's in your water.
Or you can have your water analyzed in a lab set up for such
purposes. A smart thing to do is use a meter which measures
dissolved solids (EQ, or PPM - this is a parts per million meter).
You should have one at hand at all times.
One thing to watch out for: most city water supplies have
carbonates of magnesium and calcium. Plants need these chemicals
but not over 75 PPM for magnesium and 200 PPM for calcium.
Water temperature is also important. Root areas of most plants
prefer 65 to 80 degrees Fahrenheit (18-27 Centigrade). Winter crops
will want this to be a little cooler; tropical plants will want it
to be a little warmer. Beware of abrupt temperature changes.
City water supplies are usually too high in pH, so you will have to
correct for this. pH is all right for most plants if it fluctuates
between 5.5 and 7.0. In fact the feeding of the plant roots will
cause this fluctuation. The only time to do anything is when the pH
goes below 5.5 or above 7.0.
But check your ph meter first - it could be out of adjustment. As
always, when in doubt read the instructions which came with the
instrument. Or re-check with another method.
What about your media?
Cheap stuff will give not only cheap but bad results. You can get
plenty of high pH readings with some media, such as gravel. So take
a sample and place it in a bowl of distilled water. Then check the
water's pH daily for a week to ten days. Media problems have forced
many growers to grow by using the various water methods and no media
at all.
Want to know when to change your nutrient?
Here's a simple way which will do the trick without a lot of
guessing and tortured detours. Each plant has its own appetite, so
you need something simple to keep up with all crops. You just need
to keep your eye on things and to keep records of what you see.
When you start out with a freshly filled tank of nutrient solution,
read the pH and EC of the solution. Write it down and the date.
Then, as the plants grow and the nutrient level in the tank falls,
take a reading again of the pH and EC. Use fresh water to fill to
the top. Check again for ph and EC. If the nutrient strength of the
solution drops quite a bit, add some nutrient to the solution.
Each time you add water, write down the amount. When the total
additions equal tank capacity, drain the tank and start all over
with a completely new and fresh supply of nutrient solution.
Simple and effective. And no guessing required.
Pathogens in nutrient solutions can be a seasonal problem:
The best way to avoid them is to keep a clean house. Don't let any
dirt get into the system, either by chance or intent. You can do
what a lot of growers do: at the work area doorway put a mat which
has disinfectant in it and make sure every one who enters the
growing area to thoroughly scrape the soles of their shoes into the
mat.
Be sure you always use completely healthy plants. One diseased plant
can ruin an entire crop. Get rid of those plants which do look
suspicious. Drain your entire nutrient solution, clean the tank and
refill with fresh nutrient solution.
Also always run with just water between every four or five runs of
nutrient. This will get rid of the salt buildup.
Does this all seem like a lot? Not really. If you keep careful
records, use the best hydroponic fertilizer available and carefully
measure it out, use a "chiller" for nutrient solutions in summers
when the root zone becomes too warm, you will become a grower who
knows how to deal with his plants and who wants to produce a
quality product.
Then you will become a true professional which is what hydroponics
needs.
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2. Equipment failures
Don't have enough to fret about. Well here's some more.
The climate inside a greenhouse is not conducive to keeping your
equipment in top shape. Suppose a main nutrient supply pump goes
out and you are not forewarned? Or an exhaust fan suddenly quits
working? And how about those intake fans? Plants have to get rid
of old air and have fresh air.
Pumps are especially a problem. You often don't know they have
stopped running unless you continually check them. (A computer
sensor would come in handy here!) When was the last time you made
a scheduled maintenance on your pumps?
If you're using sodium or halide lights, you have to remember that
they heat up the air around them and make arrangements to be sure
your exhaust fans are working properly.
Maybe you have a leak in your nutrient tank and don't know it. What
if it goes dry on you? And suppose someone comes in and steals your
Sodium or Halide lights? If you use lights, you need to know that
they are prime targets for thieves.
And woe upon woe: what about a power failure? Do you have a backup
for that? A power failure can put your timers out of whack. This can
mess up your feeding and lighting schedules.
A computerized sensor system could help you avoid most of these
problems. And even help correct them.
HYDROPONICS IS DETAIL! So pay attention and prosper.
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3. Here and there
a. Raspberries can be grown hydroponically - if the container is
large enough and properly designed to slow down the plant's
tendency to produce a lot of suckers.
b. A former member of the Hydroponic Society of America (of which
we also are a member) has for some time now been conducting
hydroponic workshops for teachers. Like a covered wagon, the
hydroponic workshop is brought in white van to each school site
where hydroponic information is dispensed. It's done mostly in
California, though.
c. Perhaps I've talked about this before, but it still bears
repeating. If your house or other structure has been invaded by
ladybugs, they may now be hidden behind the walls. But as the
days grow longer, they'll soon come crawling back into your
living space. Ugh!
Well courage, take heart! There should now be on the market a
device for controlling these little darlings. A USDA entomologist
by the name of W. Louis Tedders has come up with a device which
might ease your problem. The device utilizes blacklight to
capture the ladybugs and then you can hold them over in a secure
place until spring when once again you can free them in your
garden (or greenhouse) so they can do the job they're supposed
to do.
Please note: I don't know the name of the product, so you will
have to do some question asking when you go to your dealer.
Just remember when you see one ladybug in the fall, you know
that at least 300 aphids or other crop-destroying pests have
been consumed. Especially if it's an Asian variety which seems
to have invaded most of the United States.
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4. A few ideas on aquaponics
We all know that water quality is very important in hydroponics,
but it's as equally important in aquaculture. Fish, like humans, do
best in clean surroundings, including the water they swim in.
Fishermen know this well and so do good aquaponists.
For those who don't already know, aquaculture is a growing technique
which combines the raising of fish with crops grown hydroponically.
The waste from the fish as they grow becomes the nutrient for the
crops either above or in a separate facility. It is a technique
which the Chinese have been using in a rudimentary form for a long
time.
What are the advantages of aquaculture. Obviously, one gets a
continual harvest of fish. With the affluent from the fish tanks,
crops can also be grown which doubles the growing capacity of a
given area. Another desirable feature is that you can do this in
almost any climate.
You don't need large supplies of hydroponic fertilizer to grow the
crops, thus reducing your costs significantly. Properly done, the
plants of your crop purify the water which is then returned to the
fish tanks. This helps to protect ground water supplies.
In addition, you are not restricted to just one crop.
You can diversify.
What can be grown? Lettuces such as Red Oak, Mignonette, Butter,
and a number more are some of the crops which can be grown. Herbs
also are a possibility, such as basil, chives, coriander, and
parsley.
If you want to know more details about aquaculture, contact
Mr Andrew de Dezsery, Aquaculture Advantage, P O Box 582, Two Wells,
South Australia 5001, Australia. The email address is:
aquaculture@technologist.com.
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5. For a good mesclun mix...
You just knew I would sooner or later return to this topic, didn't
you? It's no secret I love a good salad, and for me a judicial
mesclun mix just can't be beat. I good mesclun mix should combine
many elements to give taste and contrast.
For example, if you know how each item tastes and its texture, then
you will have a better idea of what the final salad will be.
Radicchio has the color and some bite to it. French sorrel is sour
and lemony. Good King Henry is a substitute for spinach. Florence
fennel gives flavor as well as an appetizing fragrance. Flowers
such as carnation, nasturtium, rose and daylily do the same.
The list goes on. Including crookneck and zucchini squashes which
are picked when they are 3-4 inches long. Just use your imagination.
But do not forget the sauce! It too can be dressed to fit your
tastes and expectations. For example, you can take several flowers
from tuberous begonia, bruise them a bit and then place them into
one of your best vinegars and thus add more flavor and taste.
You can use top-grade olive oil or one of the following oils:
apricot, walnut, hazelnut, grapeseed, almond and others. These
oils mixed with a berry vinegar will just carry your taste buds
away!
I tell you there's no end to that whole world of taste and flavor
waiting for you to explore. What's most important, you can grow it
all yourself where your expense will be next to nil, nada! For
information on how to do this just go to my site on "Grow Gourmet
Salad Greens" at (http://www.mayhillpress.com/salad.html).
And, of course, bon appetit!
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