What is pH?

The pH scale measures how acidic or basic a substance is. It ranges from 0 to 14. A pH of 7.0 is neutral. A pH less than 7.0 is acidic, and a pH greater than 7.0 is basic. Each whole pH value below 7.0 is ten times more acidic than the next higher value. For example, a pH of 4.0 is ten times more acidic than a pH of 5.0 and 100 times (10 times 10) more acidic than a pH of 6.0. The same holds true for pH values above 7.0, each of which is ten times more alkaline—another way to say basic—than the next lower whole value. For example, a pH of 10.0 is ten times more alkaline than a pH of 9.0.

Why care about pH?

In soils or growing media, pH strongly influences the availability of nutrients and the presence of microorganisms and plants in the soil. Certain plants require a particular pH range to enable the required nutrients to be consistently available to the plant. If the solution is too acidic or too alkaline it can cause “lock up” – a situation that restricts certain elements essential for growth from being absorbed by the root structure. This in turn reduces plant heath and performance. Deficiencies in the required elements become apparent in plant growth and can lead to crop failure.

pH & Your Soil

Outdoors, soils have a natural tendency to acidify, thanks to rainwater. You may have heard that acid rain is a form of pollution—and it is—but all rain is slightly acidic, with a pH of about 5. That’s because the hydrogen in rainwater reacts with the carbon dioxide in air to form carbonic acid. Extreme pollution can drop the pH of rain to 4.  Minerals in soils can also affect their pH. A chalky soil has plenty of calcium carbonate, a famous antacid, which buffers the pH of soil and keeps it from becoming acidic.

How do you test the pH of your Soil?

There are a few different ways to test pH levels in soil. The most accurate but also most expensive route is to use an electronic pH meter, such as the Bluelab Soil pH Probe. This is a device that is inserted into the soil and gives an accurate digital reading. If you want to do things a little more basic, you can use litmus paper. The downside of this method is that it doesn’t give you an exact pH reading; it merely tells you whether your soil is acidic or alkaline.

Bluelab Soil pH Probe

This non-refillable soil pH probe is used to measure the pH levels of soil or media of cropping, pasture, containerized plants, home gardens, propagation culture, or anywhere that the soils pH requires testing.  This probe can be used for direct pH measurements in soils.   The soil probe is supplied with a ‘dibber’ – the green spear pictured to the right. The ‘dibber’ is inserted into the media/soil prior to inserting the pH probe to ensure no damage occurs to the probe tip from coarse soil particles or stones.

Main Features:

• Fully waterproof
• Supplied in a lockable protective case
• Calibration solutions included
• Simple push button calibration
• Auto turn off function (extends battery life)
• Large easy to read LCD display
• Low battery indicator
• 2 x Alkaline AAA batteries included
• Lightweight and portable
• 5 year Bluelab Guarantee (6 month guarantee for probe)

What is the Difference Between Recirculating and Drain to Waste Systems?

There are two forms of hydroponic systems – there are re-circulating and drain-to-waste systems. In a recirculating system, the runoff from the nutrient solution is collected, replenished and reapplied to the substrate. In a drain to waste system, the runoff is drained into the ground or routed to a holding reservoir. Many gardeners choose to use the drain to waste system because this method offers more control over the composition of the nutrient solution being applied. In a recirculating system the solution will gradually become unbalanced, unless the solution is tested for each nutrient. A rapidly growing vine crop such as tomato can remove a considerable amount of nutrients in a day. In a “drain to waste” system the grower can increase the feeding time and be confident a balanced solution is reaching the crop.

Why Run a Drain to Waste System?

• Drain to waste requires less maintenance due to the fact that the excess nutrient solution isn’t recycled back into the reservoir, so the pH of the reservoir should not vary.  A recirculating system can have large shifts in the pH levels that require periodic checking and adjusting.  If the pH is not corrected, various problems may occur, including but not limited to poor nutrient absorption.

• In a recirculating system, pathogens can quickly spread their colonies and infecting other plants in the same reservoir. With drain to waste systems this cannot happen because any water leaving a given plant goes to a drain and not back to the main reservoir.  Therefore the spores cannot infect the reservoir.

• Drain to waste systems allow you to flush your garden more easily, allowing you to reset the medium and draw out unwanted nutrients from within the plants themselves. In a recirculating system, flushing will pull the salts out of the medium as well as the plant, draw them into the reservoir, and then keep pumping them back into the plants again and again, until the reservoir is drained and the cycle is repeated a few times. Since you’re trying to leach nutrients from the plants, it makes sense that you don’t want to keep recirculating them into the garden.  By using a run to waste configuration, the nutrients are flushed out of the system completely.  All salts and excess minerals are drained from the plants and truly flushed away.

What Are The Disadvantages of Drain to Waste Systems?

• The main drawback of a drain to waste pass system is that fertilizer is wasted. In general, about 15% to 20% of the nutrient solution applied is runoff. This is not a large amount given the control over nutrition that is possible. As technology becomes available that allows for the testing and replenishment of individual nutrients, a recirculating system that provides a balanced feed, without the waste, will be possible.

Fluorescent lights work by placing an anode and a cathode at opposite ends of a glass tube. Inside the tube are a partial vacuum and a small amount of mercury vapor. When energized, the mercury vapor is ionized and emits ultraviolet radiation. The inside of the tube is coated with a phosphor – a powder that “fluoresces” (gives off light) when stimulated by ultraviolet radiation, thus producing visible light. The chemical composition of the phosphor determines the spectrum or color of the emitted light.

Although fluorescent lights are very energy efficient, there is a phenomenon known as “cathode decay” that causes, over time, less energy to be transferred through the mercury vapor. The net effect is that the tube will emit less and less light as it gets older. To all appearances, the tube will put out the same amount of light until it suddenly stops dead one day, (which can take years), but for all practical purposes, because the drop off in light output is an exponential decay, the tube should optimally be replaced at least once a year.

Fluorescent lamps are labeled according to the diameter, for example T5, T8, or T12. The number following the T refers to the diameter in one-eighth inch increments: 
T5 = 5/8″ diameter, 
T8 = 1″ diameter, and 
T12 = 1 1/2″ diameter.  Figure 2 shows diagrams of lamp ends of T5, T8, and T12 lamps. The bulbs typically come in 2-foot and 4-foot lengths. The 2-foot length works well if space is limited.

Normal output, also known as standard fluorescent lights (T8 & T12), are generally suitable for seedlings but will not provide enough photosynthetically active radiation to support robust and vigorous growth. For high-energy plants, you will want to consider using a high output T5 during the vegetative stage of growth. While plants can flower under a fluorescent light, the results will not be as impressive.  However if the grower has no other option, they may want to swap their cool spectrum fluorescent tubes for warm spectrum during flowering.

There are also compact fluorescent lights (CFL) available, which take the cool burning fluorescent technology and pack it into a focused, high output “bulb”, that you can use not only for propagation, but for growing larger plants as well. Compact fluorescents work in specially designed reflectors that efficiently direct light to the plants, much like high intensity discharge lamps. However they have relatively poor light penetration and lower overall efficiency as compared to other types of lighting.

What Are Earthworm Castings?

Earthworm Castings are the excrement left behind by worms after they finish digesting the organic matter that makes up their diet. They are made in a container filled with moistened bedding and redworms. With food waste and with assistance from microorganisms, the worms will convert bedding and food waste into compost. Worm composting can be done year-round, indoors in schools, offices and homes. It is a natural method for recycling nutrients in food waste without odor. The resulting compost is a good soil conditioner for houseplants, gardens and patio containers.

5 Benefits of Earthworm Castings

1. 1. Earthworm castings have over 60 micronutrients and trace minerals, including calcium, magnesium, nitrogen, phosphates and potash.
2. 2. Castings act as a barrier to help plants grow in soil where the pH levels are too high or too low. They prevent extreme pH levels from making it impossible for plants to absorb nutrients from the soil.
3. 3. The humus in the castings extracts toxins and harmful fungi and bacteria from the soil. Castings therefore have the ability to fight off plant diseases.
4. 4. Castings have the ability to fix heavy metals in organic waste. This prevents plants from absorbing more of these chemical compounds than they need. These compounds can then be released later when the plants need them.
5. 5. Castings are also an effective way to repel white flies, aphids and spider mites and any pest that feeds on plant juices. According to recent studies, applying earthworm castings to the soil around your plants increases the production of a certain enzyme that is offensive to these insects.

How Can You Use Earthworm Castings?

You can use your worm castings immediately, or you can store it and use it during the gardening season, or whenever. The compost can be directly mixed with your potting soil or garden soil as a soil amendment, which helps make nutrients available to plants. Or, the compost can be used as a top dressing for your indoor or outdoor plants.  You can also make “worm tea” with your castings.  The resulting “tea” helps make nutrients already in the soil available to plants.

Big Worm from Roots Organics

Roots Organics Premium Worm Castings is a distinctive natural soil amendment. Their worms are carefully tended and fed an unparalleled blend of organic compost, rock dust and kelp for exceptional quality castings. In addition to containing nitrogen, these carefully formulated castings also contain small amounts of phosphorus and potassium and naturally occurring micronutrients, minerals and beneficial bacteria.

One of the first choices you'll have to make in your life as a gardener is settling in on the system that you're going to use to grow your plants in.  It can often be difficult to choose which type of system to use because there are so many different systems available.  In this article we will take a look at various grow systems, including drip systems, ebb & flow, deep water culture (DWC), Nutrient Film Technique (NFT), Aeroponics and Aquaponics. There are hundreds of variations on these basic types of systems, but all hydroponic methods are a variation (or combination) of these.

Drip Systems

With the drip hydroponics growing system, the plants are in their own tray, separate from the nutrient reservoir. Plants are fed individually by a connection of feeding tubes, which is connected to a pump. The pump is controlled by a timer, which activates it to pump nutrient solution through the tubes and feed each plant from the top. Different emitters can be placed on the end of each tube to make the drip slower or faster. The waste is then either recirculated or discarded, depending on how the system is configured and what growing medium is being used. Use House & Garden’s Drip Clean to prevent salt and mineral build up, keeping your drip system running cleanly.

• Versatile - The water application rate can be tailored to fit each plant. This is accomplished by the use of different quantities of emitters and emitters with different discharge rates.

• Suitable for Any Grow Medium – Drip systems can be run using any type of grow medium, ranging from coconut coir to rockwool to expanded clay pellets, even in a specialty soil-based medium.

Ebb & Flow (Flood & Drain) Systems

Ebb and Flow is a form of hydroponics that is known for its simplicity, reliability of operation, and low initial investment. Also called 'Flood and Drain’, it is a system of arranging containers filled with inert growing media. The medium anchors the roots while a hydroponic nutrient solution is alternately flooded and allowed to drain.

• Simplicity – An ebb and flow hydroponics system is quite easy to build, use and manage, as it doesn't require a lot of technical knowledge to set it up and keep it running. Even better, if you're not building it yourself, it's almost plug-and-grow easy.

• Aeration - The ebb & flow method supplies fresh oxygen to the root system of plants in two ways. First, as the tray is flooded with nutrient solution, carbon dioxide rich air is pushed out from around the root system. When the pump is turned off, the tray is drained and oxygen rich air is drawn down to the roots. The plants then use this oxygen until the next cycle begins

Deep Water Culture (DWC))

Deep Water Culture (DWC) is a hydroponic method of plant production by means of suspending the plant roots in a solution of nutrient rich, oxygenated water.  With this system, the roots of the plants are submerged in the nutrient solution. The plant is then held in the proper position through the use of a net, which ensures that the top of the plant is not in the nutrient solution, only the roots. As the roots are constantly submerged, it is crucial that the air pump is on 24 hours a day. If the pump is allowed to be off for any length of time, the roots will suffer.

• Highly Oxygenated - Plants exposed to greater levels of oxygen in and around their roots will subsequently enjoy unparalleled root development and prolific overall plant growth. This is because aerating the root zone radically improves water absorption, nutrient uptake and cell growth/activity within your plants.

• Low Maintenance - DWC hydroponics systems are simple by design and require very little attention – the pumps are on all the time, so no timers or controllers are needed. There are no spray nozzles, return lines, feeder lines, or water pumps to clog, and no reservoirs or float valves to overflow or jam.  Other than grower error, the worst thing that can go wrong is if the air stone stops working. This can be easily avoided by checking your stones, pumps and lines daily.  Always keep a spare air pump in case of an emergency.

Nutrient Film Technique (NFT)

The nutrient film technique (NFT) is a widely used hydroponic method for production of short harvest vegetable crop, such as lettuce and basil. The basis of the NFT method is a network of shallow pipes, tubes or trays that contain plants and deliver a continuous flow of a nutrient solution over the enclosed plant roots. The plants are housed in net cups suspended in the tube, set on a slope to assist in the flow. The roots will then grow into the nutrient film that passes over them.  The level of the solution is kept just high enough to maintain a thin film of nutrient-bearing water moving over the roots.

• Versatile – NFT systems are easy to move around, modify, expand or contract the system configuration.  Because channels are on sliding bench, they can be moved closer together or further apart to accommodate seasonal plant size fluctuations and/or crop modifications.

• Easy to Use - This system isn't very complicated at all. The limited amount of equipment means that there is a lot less that can go wrong. Simply run your pump 24/7, day and night. There’s no need to work out irrigation cycles and frequencies. Your plants will simply absorb as much or as little nutrient as they require.

Aeroponics

In an aeroponic system, nutrients and water are sprayed onto the roots in an atomized or mist form by a high-pressure pump. This creates quickly moving water, which is capable of delivering more oxygen because it is well agitated, like a waterfall. The presence of more oxygen also discourages bacterial and fungal growth.

• Less Need for Nutrients & Water – Aeroponic plants need less nutrients and water on average, because the nutrient absorption rate is higher, and plants usually respond to aeroponic systems by growing even more roots. The operating costs for an aeroponics system also tends to be lower.

• Requires Little Space – You don’t need much space to start an aeroponics garden. Depending on the system, plants can be stacked up one on top of each other.  Aeroponics is basically a modular system, which is perfect for maxing out limited space.

Aquaponics

In aquaponics, the nutrient-rich water that results from raising fish provides a source of natural fertilizer for the growing plants. As the plants consume the nutrients, they help to purify the water that the fish live in. A natural microbial process keeps both the fish and plants healthy. This creates a sustainable ecosystem where both plants and fish can thrive. In this symbiotic relationship, fish waste provides a food source for growing the plants; and the plants supply a natural filter for fish.

• Natural Approach – Instead of adding toxic chemical solutions to grow plants, aquaponics uses highly nutritious fish effluent that contains almost all the required nutrients for optimum growth. This method provides a truly organic, natural form of nutrients for the plants.

• Supports Symbiotic Relationships – The symbiotic relationships formed in an aquaponic system create very complex ecosystems that actually increase the level of production when compared with the individual methods.

Perlite
One of the most common inorganic substrates is perlite. Perlite is super-heated to expand into lightweight, porous rocks that provide excellent aeration and improve the drainage and compaction of any medium such as soil, coco, or peat. Perlite will also wick water to your root zone and can be used as a medium for cloning shrubs, bushes, and woody stemmed plants. Perlite is inexpensive and comes in various sizes all smaller than or equal to the size of a marble.

Expanded Clay
Another common inorganic medium is expanded clay. Expanded clay is used in hydroponics and other applications where a strong, reusable medium is necessary. Expanded clay, such as Hydroton, is reusable, durable, and can withstand high volumes of water without compromising the medium. Expanded clay is porous, allowing more surface area for plant roots to colonize and will also retain moisture. This will allow your plants to absorb more water and nutrients over a longer period of time compared to other rock based growing media.

Rockwool
Rockwool is a volcanic rock that has been super-heated and spun like cotton candy to make small woven fibers that contain air pockets. These air pockets, when moistened, create an ideal air to water ratio for plant roots; oxygen easily travels in and out of the root zone, creating explosive root growth and a healthy aerobic root environment. Rockwool can be reused, however over long periods of time it will compress and lose the air pockets that make it so useful.  We do not recommend using rockwool in hydroponic systems because dead root matter can be difficult to remove completely and can lead to harmful pathogens that may harm your plants. It can however be composted and will break down naturally over.

Growstones
Next we have Growstones. This medium is made from recycled glass that has been heated and expanded into large porous rocks. These stones will perform similar to expanded clay, however are less dense and is more lightweight than expanded clay. Another difference between the two is the cleanliness of the stone itself. A mild rinsing of the stones will clean any debris off of them, whereas expanded clay tends to be more tedious to properly and thoroughly clean.

Silica Rock
Another rock substrate common to horticulture is silica rock. Silica rock is used to provide slow release silicon into the plants cells and is also used as a versatile, reusable hydroponic medium. Silica rock, such as Higromite, is a slightly larger rock, yet performs very well in hydroponic systems because of its strong, dense structure. There is little to no breakdown of material over long periods of time with heavy exposure to water and sunlight. Finally, it will provide slow release, natural silicon to your plants throughout the entire life-cycle. This will strengthen your plants and increase their resistance to extreme environmental conditional while saving you money on silicon supplements.

1.    How often do I want to water my garden?
2.    How often do I want to fertilize my garden?
3.    What type of plants are we growing?

The answers to these questions will make it much easier for you to choose the right soil blend for your crop. Sure, you can spend years trying “this and that” on your own, but if you want professional results now, read about what we’ve learned already.

If you want to keep it simple, try a complete soil blend that already has all of the macro and micronutrients your garden needs. For example, Sanctuary Soil and Feed recently introduced their Empire Builder brand of potting soil. The Empire Builder Producer’s Blend from Sanctuary is a great all in one mix that contains premium ingredients derived from sustainable sources.  Since this soil blend does run “hot” (contains a high concentration of nutrients), avoid planting seedling and young plants in this mix. We recommend watering with little to no additional nutrients in the early stages of growth. The inclusion of greensand in the Producer’s Blend gives this soil great water retention, making it a good choice for outdoor use.  Though it’s not indicated on the bag, the Producer’s Blend is an organic soil.

For those of you that like to take a more hands on approach in regards to feeding schedules, choose a soil that does not contain such a high amount of nutrients. Roots Organics Original Potting Soil is an excellent choice as a foundation for any nutrient feeding program. Unlike typical potting soils, Roots Organics adds coco coir to their peat base and contains higher amounts of perlite, allowing for better drainage. This soil is safe to directly transplant your veggies at any age. We recommend using fresh water and mild compost teas for a couple weeks. After that, you can proceed using the plant food of your choice carefully following the feeding schedule.

Many gardeners are now making the switch from soil to coconut coir as a base medium.  Using an inert (free of added nutrients) medium like coco coir allows you to use a more advanced feeding program like House & Garden’s Cocos A+B. Coco is not soil, but you do get the same natural feel of soil when you work with it. Plus it’s a renewable and sustainable growing medium. Since coco doesn’t contain added nutrients, you know you are getting a consistent product every time. Coco offers superior aeration for your roots, but doesn’t dry out so quickly that you have to water everyday. Mix perlite into your coco if you want to water your plants more frequently.  Feeding your plants more often can help achieve higher yields. When gardening in coco, you can use your nutrients at full strength whether organic or synthetic. We recommend using House & Garden’s coco coir because it is very clean and pH buffered.

So to recap, if you want to water more often, use a medium that has better drainage – for example, look for a soil with more perlite. If you want to water less often, look for a soil with greater water retention properties – choose a medium with higher peat moss content. If you want to fertilize more frequently, then start with a blend that has little to no nutrient value. To feed less frequently, use a “hot” soil that comes rich with amendments. Because there are so many plants with different nutrient requirements, research the specific needs of the variety that you are growing.

We want you to be successful in your garden so if you have any questions, visit any of our stores for answers or visit our Ask A Grower service at http://sdhydroponics.com/ask-a-grower.