Hydroponic Fertilizer Experiment Update #2

Fertilizer Experiment Update

Fertilizer Experiment Update
APTUS & Heavy 16 on Left / GH Flora Duo on Right

Time for another update! We started our experiment testing Heavy 16 fertilizers and APTUS additives versus General Hydroponics’ Flora Duo a little more than 2 months ago. We are growing super hot peppers called Trinidad Scorpions, and they have really taken off!

To refresh your memory, or if you’re just joining us for the first time, the experiment is set up with separate drip to waste reservoirs, feeding individual plants in the same 4′ x 4′ Botanicare grow tray. All of the plants are being lit by a single 400 watt High Pressure Sodium Hortilux SUPER HPS bulb. Here are some numbers for all of you keeping track:

Fertilizer Experiment Metrics

Fertilizer Experiment Metrics

And now for some more pictures:

All Plants in the Experiment

All Plants in the Experiment

GH Plants

GH Plants

Heavy 16 & APTUS Plants

Heavy 16 & APTUS Plants

Monster Branching on GH Plant

Monster Branching on GH Plant

Monster Branching on Heavy 16 / APTUS Plant

Monster Branching on Heavy 16 / APTUS Plant

Hydroponic Fertilizer Experiment Update

Aptus Experiment week 4

Heavy 16 and Aptus vs GH Flora Duo Experiment WEEK 4
Flora Duo plants  in the Foreground, Heavy 16/Aptus plants in the back

We started our experiment (which all of you voted for) about a month ago: testing Heavy 16 fertilizers and APTUS additives versus General Hydroponics’ Flora Duo. Although super hot peppers (like the Trinidad Scorpion) are fun to grow, they do not grow quickly for the first few weeks. At four weeks in, these young pepper plants are growing vigorously, but it is too close to call…

The experiment is set up with separate drip to waste reservoirs, feeding individual plants in the same 4′ x 4′ Botanicare grow tray. All of the plants are being lit by a single 400 watt High Pressure Sodium Hortilux SUPER HPS bulb. Check back soon for more results.

Heavy 16 and Aptus Experiment

Heavy 16 and Aptus on Left, GH Flora Duo on Right—Top View

Which Hydroponic Fertilizer is Best? Experiments with a Purpose!

plant science experiments favorite hydroponic experiment

Choose your favorite hydroponic experiment. Photo courtesy of freedigitalphotos.net

Have you ever wondered to yourself which hydroponic fertilizer works best? Do I really need to use all 14 products from “that” nutrient company? Will adding this product make my plants grow like Jack’s beanstalk? Well now is your chance to find out. I am always running experiments here at Atlantis Hydroponics. I trial new fertilizers, test the latest “must have” additives, and perform simple side by side experiments to determine what works, and what does not. Now is your chance to choose the next experiment I conduct. You choose what you want tested, & I will blog the experiment and the results. So here it goes; the possible experiments are:

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Canna Lovers, Get all your Canna Nutrient and Coco questions answered at the Atlanta West Midtown location by a Canna Nutrients Rep, along with prize giveaways, and complimentary snacks and refreshments!

Web Shoppers, order Online and receive 15% off orders placed 11/17.

Use hydroponic promo code ILOVEHYDRO at checkout.

Lumens are for Humans but PAR is for Plants!

Prism Splitting Light

Prism Splitting Light

It blew my ten-year-old mind when my “all knowing” grandmother told me that the Blue Jay we were watching was in fact not blue. She explained that light is composed of many colors, and it is the colors that are reflected, not absorbed that our eyes perceive as the color of an object. This is a necessary reminder that what is perceived might not be what it appears to be. For decades the indoor gardening community has used Lumens as the standard increment for the measurement of light. Lumens were unfortunately a poor choice, here’s why.

Diagram of How a Prism Works

Diagram of How a Prism Works
coutesey of freedigitalphotos.net

Lumens are essentially a measure of brightness based on human perception. Precisely, a lumen is equal to the light emitted by one candle falling on one square foot of surface located one foot away. This however presumes a human as the perceiver of the light. Plants “perceive” light differently; from a plant’s perspective, light that is useful for photosynthesis is not necessarily bright. Light, or more specifically, visible light is made up of wavelengths of energy on the electromagnetic spectrum ranging from 380-770 nm (nanometers). Plants utilize wavelengths from 400-700nm for photosynthesis. Brightness does not accurately describe if the light will be more or less useful to a plant.

Light can be characterized in other ways when discussing its benefit to plants. Color temperature is often referred to in the horticultural industry on lamp boxes to describe the color of the light emitted by the lamp. Does 4,000K grow a plant better than 7,500K? Color temperature is listed in Kelvin (K), which is a measurement of temperature. The temperature of what you might ask? It is a description of the relative whiteness of a piece of tungsten steel when heated to that particular temperature in degrees Kelvin. This accurately characterizes the color of the light as we perceive it, but color temperature again fails to address how effective a particular light source will be at providing the energy necessary to drive photosynthesis.

Don’t get frustrated by this inadequate information. There is in fact a measurement that precisely describes how effective a particular light will be for growing plants; PAR (Photosynthetic Active Radiation). PAR spectrum accounts only for light or more precisely photons emitted between 400-700nm. Scientists have concluded that it requires about 9 photons to bind one CO2 molecule in photosynthesis [6CO2 + 6H2O (+ light energy) C6H12O6 + 6O2]. Even though blue photons have more energy it has also been found that there is little difference between the effectiveness of red versus blue photons at driving photosynthesis as long as the photons are within the 400-700nm range. This leads to a direct correlation between the number of photons produced in the PAR spectrum by a given light, and the photosynthetic potential of that light.

Photons are emitted by light sources in very large numbers so we do not talk about billions or quadrillions of photons, instead we refer to them using the multiplier moles (which stand for 6.0221415 x 1023) To make the numbers even more accessible, the number of moles is often divided by 1 million resulting in micro-moles (μmol). Light sources emit photons continuously over time so the number of micro-moles is more accurately described as μmol/per unit of time (most commonly seconds).

When trying to quantify how effective a light source is beyond the total output of μmol/per second, you must consider one last piece of information… the size or area of your garden. Inevitably some of the photons produced will not reach your garden. So the most accurate representation of a light source’s ability to drive photosynthesis will take into account the area being lit and how many photons reach that given area per second; usually a square meters. That representation which actually summates the effectiveness of a light source for photosynthesis is written as μmol/m2/s. This descriptor is actually referred to as Photosynthetic Photon Flux Density or PPFD for short.

So in light of all of the information above, let’s remember that lumens are not a useful descriptor of a light’s ability to drive photosynthesis. I think I will sit back with a drink, and digest all of the information about PAR & PPFD while I watch the not blue Blue Jay outside my window.

Accidental Discoveries: How One Mistake Can Save Your Garden!

How Someone Else’s Mistake can Save Your Garden

How Someone Else’s Mistake Can Save Your Garden

Humankind has benefited time and time again from chance insights made during scientific research.  Among the multitude of accidental discoveries are: champagne, crazy-glue, Post-it® notes, LSD, and penicillin.  Just think how much less fun life would be without champagne and penicillin! Today I will share a story with you that will help your hydroponic garden…and you guessed it, it is a discovery that was made by accident.

In a research laboratory at a large university a lowly graduate student had the unenviable task of mixing up the nutrient solution for the department’s experiments from scratch.  This meant individually adding chemical compounds one at a time to tanks of water to build the fertilizer specifically matched to the particular experiment.  Universities often use custom formulated fertilizers to allow for a higher degree of control which also save money by eliminating pre-mixed commercial fertilizers. The student accidentally used MgCl(magnesium chloride) when they were supposed to have used MnCl2 (manganese chloride).  A few months went by and the majority of the hydroponics systems in the laboratory developed severe Pythium infections.

Pythium is one of the most common pathogens hydroponic growers contend with.  It used to be considered a fungus but has more recently been classified as an oomycete (a group of fungus like-organisms.)  Pythium can cause severe root rot and poses a huge threat to hydroponic crops.   Pythium in its spore stage can move quickly in water and multiply, reeking havoc if left unchecked.

Due to the short duration of the university experiments (about 25 day cycles) the plants did not show visible signs of being deficient in manganese.  There was enough manganese from other sources to meet the minimal needs of the plants, but there was roughly a 15% reduction in yield.  It was not until later when they discovered the student’s mistake that they made the possible connection between the lack of manganese and the increased occurrence of Pythium infections, which led to experiments designed to verify that manganese had the ability to suppress Pythium.

It is well documented that copper is able to suppress microbial growth; however, copper in elevated amounts is toxic to plants.  To this point, manganese had not been examined to see if it too had any antimicrobial characteristics.  Manganese is an active ingredient in the well known commercial fungicide Dithane®.  So it was not a stretch when their research went on to reveal that manganese and zinc (as it turns out) demonstrated some level of microbial inhibition.  Unlike copper, slightly elevated levels of manganese and zinc in your hydroponic solution are not going to cause phytotoxicity, but they may prevent a costly attack of Pythium.

The moral of the story is that there are happy accidents in science and all we have to do is learn from them!  So add some extra zinc and manganese to your reservoir, sit back and sip some champagne.  You can rest easier knowing you have added a level of protection to your hydroponic garden (and you didn’t even need to use penicillin)!

Hydroponics and Gardening: They’re Older than Epcot!

Hanging Gardens of Babylon depiction

The “Roses are not yet in full bloom here – in fact they are scarce – and from all of the nurseries and all the garland-weavers we could just barely get together the thousand that we sent you…even picking the ones that ought not to have picked till tomorrow. We had all the narcissi you wanted, so instead of the two thousand you asked for we sent four thousand.” (Stewart, pg 6)*

The quote above was not a request for flowers for the recent Olympics, nor for a recent inauguration or state funeral, it was written on papyrus before the birth of Christ. It is a stunning reminder that although we are continuing the age-old tradition of gardening we should respect the developments and advancements that were made before us. We should strive to improve our skills as gardeners and gain a better understanding of our plants, our growing systems, and of the history that has come before us!

Gardening is not new by any means, and yet hydroponics is often considered cutting edge science. The truth of the matter is that hydroponics dates back hundreds- possibly thousands- of years BC. Hydroponics was not a technique relegated to a single culture either. There were the hanging gardens of Babylon, the floating garden of the Aztecs, and ancient Egyptian hieroglyphics alluding to hydroponics. **

Let’s remember that the amazing display of hydroponic gardening at Epcot, and NASA’s work with hydroponics for the upcoming manned mission to Mars, owe their progress in some part to these ancient cultures.

*Stewart, Amy, Flower Confidential, Workman Publishing, 2007.

**Resh, Howard, Hydroponic Food Production . Woodbridge Press, 1997.

How to Yield 30 Lbs. from One 600 Watt HPS Grow Light!!!

Hydroponic Black Krim Tomatoes

Hydroponic Black Krim Tomatoes grown with Canna Nutrients

Just to give you all a taste of what is possible, try growing 30 lbs. in 16 weeks from seed under only one 600 watt HPS light. This is not just theoretically possible but actually accomplished by Atlantis Hydroponics.

 The Set-Up:

From January 1st 2011 when the seeds were planted until the last of the fruit was ripe and picked Atlantis Hydroponics’ own, Scott from Chattanooga TN grew the Black Krim strain of tomatoes with ease using the Canna Aqua series of nutrients.
They tasted even better then they look!

Field Trip with Doctor Dave

Today we had an adorable group of kids from Muslim University of Islam Private School here in Atlanta. Doctor Dave gave them a great tour around the store and a detailed explanation of how hydroponics began and how it can be used to grow big, tasty plants!

There was a lot of smelling, touching and looking at all the basil, oranges, and bananas.

As you can tell, the kids had a wonderful time and enjoyed all the wonders of hydroponics.

A Bug Army For Your Garden

Last blog I wrote about controlling harmful insects using pesticides and an Integrated Pest Management approach.  A necessary part of any IPM program is the use of beneficial insects.  Think of them as your own little army fighting for a pest free grow-room 24/7/365.  Having released thousands, yes thousands of Hippodamia convergens (ladybugs) in my grow-room I will say I became more comfortable with insects crawling on me but 99% of the time they were on the job, on a search and destroy mission for any pest intruder attempting to sabotage my garden.  There are lots of beneficial insects to choose from but you must match the pest to the predator, although many predators are not picky and will eat a variety of harmful insects.  Using the chart below you can easily match the kind of insect problem you may be experiencing with the correct predatory insect.

Beneficial Insect IPM Chart

Some interesting facts regarding these insects are:

  • You never should worry about your beneficial insects eating your plants as they will only feed on harmful insects
  • One Lady Bug may eat 5,000 aphids in 1 year
  • Green Lacewings will eat 200 aphids a week
  • Spider mite destroyers will eat 40 mites a day
  • Predatory Nematodes will kill over 250 different types of insects