Lettuce Harvest from Hydroponic System December 31st, 2010

Here is the latest video update showing lettuce harvest, a discussion on nutrient usage, lighting hardware, and my thoughts on the deep water culture and ebb and flow systems. 

I am truly astounded at the speed of growth and minimal nutrient usage!!

Grow Light Expenses????

   Ok, so how much does it cost to purchase and operate artificial lighting?

   Lighting expenses continue to be a concern for my indoor growing endeavor because I want to keep this cost neutral or preferably net positive if at all possible. After all, this is "Frugal Hydroponics" right?

   The lights I use are simple 2-bulb, 32W, T8, 48" shop lights with on/off pull chains. "T8" fluorescent bulbs are much more efficient than the standard T12 40W bulbs. "T5" systems are more expensive for the initial purchase, but are more efficient than the T8s. I may switch to T5 in the future, but for now I am happy with the results and efficiency of the T8 system.

   I bought 3 of these shop lights for less than $9 each and fashioned them together to operate as one 48", 6 bulb fixture of which all are plugged into the same light timer. In effect, I have 6 32W bulbs covering a 48" x 24" growing area. This easily accommodates several standard starter trays or least 3 of the hydro systems. I recommend watching your local big box stores for sales and manufacturers rebates. The lights I bought normally retailed at over $20 each, so wait for the sale.

   Since vegetative growth is achieved in the "blue" spectrum, I use 6500k bulbs. A 2-pack of Sylvania T8 6500k bulbs is around $3.50. Since I am growing lettuce, herbs, and my spring starters, the blue spectrum is all I need. If I were to grow plants requiring a flowering stage (peppers, cucumber, tomatoes, decorative flowers etc.), I would need red spectrum bulbs and additional shop light fixtures. At this point, I believe that is cost prohibitive for me as I will grow those type plants outdoors.

   Calculating Energy Consumption: 32W bulb x 6 bulbs = 192 watts. 14 hours of use per day x 30 days = 420 running hours. 420 running hours x 192 watts = 80640 monthly watts used. 80640 / 1000 = 80.64 Kilowatts used. My energy company charges $.0783 per kilowatt, so my total monthly expense to run these lights is $6.31.

   Expense re-cap: Total cost of shop lights: $27. Total cost of bulbs (replace yearly): $10.50 or $.875 per month. Total energy usage per month: $6-$7.

   I feel this is economically feasible for the production I am wanting to achieve. I recommend researching "High Intensity Discharge" systems for anyone wishing to produce flowering plants or increasing production by several magnitude. These systems do require many additional considerations, so research diligently.

Design and Build of the Deep Water Culture (DWC)

Here is a simple video explaining the design and build of the Deep Water Culture (DWC) system.   These two modules will replace the ebb and flow system as the primary growing vehicle for lettuce.  In a DWC system, the roots lay in a highly oxygenated nutrient solution while drawing dry air from the top area of the pot.  It is critical for the solution to maintain aeration or the roots will drown.

I chose a DWC and this particular design for a couple reasons.  1) A DWC is very simple and requires minimal parts (air stone, tubing, air pump). 2) This design will hold over 5 gallons of nutrient solution providing a stable nutrient base.  3) This design allows for easy replacement of nutrient solution by simply setting the lid / pots / plants aside and dumping and refilling the reservoir.

I expect the same rates of growth as I have experienced with the ebb and flow system.

Bigger and Better

We are still harvesting with no apparent end in sight.  The lettuce is greener and crisper than it has ever been.  This photo was taken today after being heavily harvested just a few short days ago!  Some sun dried tomato vinaigrette, olives, a few shreds of Romano and voila!

Steady Harvest!!

Since my last update, we have harvested lettuce for salads or sandwiches every other day.  That amounts to 2 large salads worth of growth in just 48 hours.

I have added about 2 gallons of plain water to keep the reservoir level stable, but have added NO additional nutrients since the 21st of November.  PH is staying in check as well.  This again shows how little maintenance this system requires.

The basil is beginning to shows some sign of mineral defficiency, but it is a more demanding plant than the lettuce.  The signs are minimal, but I am watching closely for the rates of change and hoping to squeeze another 7-10 days from the current nutrient batch.

Time to expand

We are steadily harvesting and eating the lettuce and using the lemon basil in some great Mediterranean dishes.  I have taken a few photos, but since we are steadily trimming the plants, there is really no need to post them. 

The PH has needed a couple very small adjustments and I have only added about a gallon of water in the past 6 days due to transpiration.  As I stated previously, it takes about 5 minutes of my time each day to monitor a couple things such as water level and PH.  Hydroponics continues to be virtually maintenance free.

I am very satisfied with the limited maintenance, high growth rates, and overall ease of use hydroponics.  It is time to expand our capacity to grow more greens and keep a crop in harvest rotation at all times.  We are getting pretty spoiled with fresh greens in salads and on sandwiches.  They are delicious!

I am still making some final decisions on the design of the Deep Water Culture system and will post when I begin the actual build.

Zzzzzzzzzzzzzzz......

Yawn.
Check water.....fine.
Check PH......fine.
Harvest lettuce........yum.
Harvest Basil.......freeze.

Talk about low maintenance! 

I will germinate the next round of lettuce seeds very soon.

Nutrient Change and details, details, details. November 21st

Over time, the plant growth nutrients are depleted at varying rates depending on the type of plant and various growth factors.  This results in a gradually weakening nutrient solution along with water loss from plant transpiration.  My original plan was to conduct a nutrient change at about the two week period and increase the nutrient dosage from 1/2 recommended strength (plants in early growth stage) to full strength.

An experienced hydroponics grower suggested I wait until 3 weeks before changing the solution.  His reasoning was that the younger the plants are, the fewer nutrients they require and they may not have used them all in only 2 weeks.  He also suggested letting the plants' appearance assist in guiding when to change the nutrients. 

I noticed slightly less color in the new leaves on the basil and that triggered my decision to change nutrients over the past couple days.  It is right at the 3 week mark, so kudos to my friend's recommendation!! Save a little time, save a little nutrient.

I replaced the solution with clean water and let it "rinse" the system for 24 hours.  This is to remove excess salts and unbalanced nutrients from the growing media and roots and allow a fresh base for the next few weeks.

After rinsing for a 24 hour cycle, I replaced the water and added nutrient at full strength this morning.  A PH check a couple hours after the nutrient change showed a bit on the alkaline side.  I added PH down and brought it to 6.5.  Too easy and very little time required.

Now that it is on full nutrients, I am expecting even greater results.

VIDEO Update, November 19th

A look at current growth and a peek at the roots under the pots.

EXPLOSIVE GROWTH November 16th, 2010

Wow!  I think the Mrs. and I both said it at the same time.  This is about double the growth I have experienced with soil for this type of lettuce.  The plants are now around 25-26 days from seed. 

I trimmed the tops of the basil to encourage more horizontal growth and to allow the lights to remain at a suitable level for the lettuce (about 2-4 inches from the bulbs).

I think we will begin harvesting the larger lettuce leaves over the next few days and now expect full harvest around the end of the month.

Simplicity

I am amazed at the growth and the vitality of the lettuce and basil in the system. I understood hydroponic growing produced superior results, but I did not expect results to this extent.


Aside from the phenomenal growth, it is the simplicity that really strikes me. I spend less than 10 minutes per day on any kind of maintenance or system tweaking. In fact, most days are spent taking a peak at the water level and the rest of the time spent marveling at the plants.


The PH tests (about every 3rd day) take all of 5 minutes said and done and adjustments to the balance (if needed) add another minute or so to the routine. I believe the decision to go with a 9 gallon reservoir was sound as it really helps to maintain the PH balance as opposed to a more volatile small capacity system.


Keeping the PH between 5.5 and 6.5 allows absorption of all nutrients across the spectrum. Too high or low can lock up nutrients and decrease the plants ability to process the needed minerals for growth. I was a little apprehensive about the PH testing and balancing, but it has proven very simple.


I am already contemplating replacing some of the soil-based outdoor containers with hydro systems. It really is so simple.

November 8th, 2010

Another 70 degree day in November!! But with daylight savings it is now dark at 5 pm, so luckily I have the downstairs project, he, he, he.

This above photo was taken today and wow! This is still on 1/2 nutrients for another 7 days!!  The lettuce is quite green, fluffy, and growing very quickly. The basil is very strong and the grow area now smells like lemons.  I can say I am very satisfied with this ebb and flow system.




The roots are beginning to really stretch from the pots. At the end of each drain cycle, there is roughly 1/8 inch of nutrients remaining in the bottom of the fill tray. It was an early concern as I could not seem to build the drain system in a manner to completely empty the tray.  After talking with a few experienced growers, I was assured the roots will quickly finish off any remaining nutrients that are left within their reach. 

Growing!!! November 5th

We are at 5 days in the system and 10 days from gerimation.  I think they are progressing very well. The PH is staying in check (6-6.5) and I have not had to top-off water levels as of yet.  I'm sure that will change soon. 

As the plants take the nutrients they need, the remainder stay in the solution which will eventually cause an imbalance.  The rule of thumb is to add water to the system as the plants deplete it and completely change out the solution after two weeks.  This change out will allow the solution to "start over" with a full set of the nutrients required for production.  I have the first change scheduled at mid-month.

This is really low maintenance.  More so than I first anticipated.  I can see expansion in the very near future!

Status and Journal 3 November

The plants are now in day 3 since their transplanting into the ebb and flow system and are looking well.  The PH has been maintained between 6 and 6.5 and the flow cycles appear to be adequate during this stage of growth.  All systems are a GO!!!!

I am keeping a written journal as well as the video log during this first run to insure I catch any lessons learned or mistakes and to insure I keep the methods that prove to work well.

Nutrient solutions, PH level, and flood cycles are the biggest learning points at this stage.

1 November 2010 and first planting

Well today is the day!!!!  I planted 5 simpson lettuce and 4 basil (4 bundled into one pot) into the newly built ebb and flow system.

The plants are under 6 48" 32W 6500k flourescents. 

The nutrients are CNS17 at 10ml/gallon strength and PH is 6.5.

Away we goooooooooooo!



or here:

http://www.youtube.com/watch?v=aJn1dOB9UOs

The setup as of October 30th

The first system is an ebb and flow and will be used to grow letuce and basil. 

The seedlings are a couple days away from transplant into the grow media.

Can't wait to get this up and growing!!!



or here:

http://www.youtube.com/watch?v=aG8HkRmwyls

Why?

Why indeed.  And how the seed was planted.  ;)

As a natural progression from raised beds and container gardening, using hydroponic techniques can create even greater efficiencies in providing fresh, organic veggies for our family.

By extending the growing season indoors, we can harvest common and exotic greens, peppers, and herbs all while the stores are increasing seasonal prices and reducing the normal summer selection.

The real test will be financial feasibilty over time.

After much study and comparison, I decided to go with an ebb and flow system as my first venture into hydro. I intend on growing lettuce, basil, and cilantro to start.


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The Ebb and Flow System, also called Flood and Drain.

I used a 56 quart and 28 quart sterilite tote for the reservoir and tray respectively. Both cost a total of $11.00 at HD. Add a can of plastic spray paint for $4.00

I purchased the following at a hydro store. Note: the cost of fittings and tubing were nominal over the comparable items at a box store.

Submersible pump $21.00

ebb and flow drain fittings $5.00

Tubing $1.50

Gallon of nutrients $26.00

6 five-inch net pots $7.00

33 lbs. silica rocks as medium $14.00 (same as hydroton)

PH test kit $17.00

6 neoprene covers $12.00

20 mil syringe $1.50

Total to get started $120.00

I already had a timer, lighting system (6500k T8 dual 48 inch fixture), an air stone and air pump.

Recurring items:

Nutrients and test solution: Around $20-$30 per year

Air stone replacement: $1.50 per year