Easy to Build Hydroponic System

One of the easiest hydroponic systems to build is commonly called a DWC (deep water culture) system. Although typically called a DWC system, it’s usually really a combination of hydroponic systems. A true DWC system is nothing more than a water culture system, with a deeper reservoir instead of a shallow one. Depending on how it’s built, most DWC systems combine a water culture system with one or more of these, drip, aeroponics and/or flood and drain systems. The easiest way to construct one is using a five gallon bucket with a lid, and a regular plastic pot. Cutting a hole in the bucket lid for the plastic pot to sit in without falling through.

The nutrient solution is placed inside the bucket where there is usually an air stone (connected to a air pump) is also placed. The air stone provides oxygen to the roots, and helps them to keep from suffocating in the water. Then the lid (with the pot) is set on top of the five gallon bucket. From there you have the basic DWC hydroponics system design. The key to the DWC system working is that the plants root system (either part or all of them) be submerged in the nutrient solution. From there you can make many variations, like if you wanted to recirculate the nutrient solution, and weather you wanted to recirculate it using a drip system, misters (aeroponic), or flood and drain. There are just to many variations to cover them all, but I will try to cover the most common ones.

Basic system
With no recirculating nutrient solution this would be the most basic, inexpensive and easiest. Without using a recirculating system the water level is very important, because the roots that are hanging in air (inside the bucket) are likely to dry out. Also the roots that are in the growing medium (in the pot) wont get any moisture and dry out. So you will want the water level to be just above the bottom of the pot with the plants in it, that will allow the growing medium to wick up the nutrient solution, and keep the hanging roots wet.

Even though it’s a basic system, there are a couple of things that will make it easier to use, and grow your plants. First is, you will want a way to drain the nutrient solution in order to make nutrient changes easier. The easiest way to do this is by simply just securely placing an end cap (or plug) on the drain tube that can be removed to drain the bucket/s. Another easy way is by installing a plastic or PVC “ball cock valve” at the bottom of the buckets.

Simply opening the valve will drain the buckets, then the new solution can be poured in from the top, right on the growing medium without even opening the lid. The next thing is you’ll want to be able to check the water level easily. A simple elbow connector installed in the side of the buckets with clear vinyl tubing running all the way up to the top of the bucket will make it easy to see the water level inside the bucket. Just make sure it’s covered when your not checking it to prevent algae growth in the clear tube.

The most common DWC/drip system
The most common DWC setup is probably the combination drip system, especially when using 2 or more buckets at the same time. Again there many variations on this type of setup you can do. But you wont need the clear tubing on the outside of the bucket for viewing the water level. You can set the water level by the placement of a overflow tube. The height of the overflow tube will keep the water level constant. Each time the drip system waters the plants, it drips down into the bucket filling it to the point of the overflow tube. The overflow tube then drains back to the nutrient reservoir, to be pumped back through the drip system again.

Because the water is recirculating between the buckets and a reservoir, the drain tube with the ball cock valve to drain the bucket with may not be needed. You will be able to just change the nutrient solution that’s in the reservoir. There will still be the nutrient solution in the buckets, but as the new nutrient solution circulates through the system, it will mix with the old nutrient solution. So whether you want a drain on each bucket depends on weather you want to be able to get as much of the old nutrient solution out as you can when doing a nutrient change.

DWC/flood and drain system
The DWC/flood and drain system is fairly simple also, and as always can have many variations as well. The only real difference is how the water is pumped to the buckets. Instead of dripping down from above, the nutrient solution is pumped into the buckets from below the plants, through the water inlet tube. Then when the pump shuts off, the water begins to drain back  down through the pump, and through the same inlet tube it was pumped up in.

DWC/aeroponic system

The DWC/aeroponic system is very similar to the DWC/drip system setup. Again the only real difference is the nutrient delivery system. Where the drip system drips down through the growing medium into the buckets, the aeroponic variation sprays the roots from inside the buckets with misters. The overflow tube would need to be low enough to allow the misters to spray the roots. But the water level in the buckets doesn’t need to be real high anyway, because the misters will keep the hanging roots moist and from drying out. But you do want it high enough to keep a good amount of water at the bottom of the buckets.

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Growing Hydroponic Raspberries, part 2

Why a Greenhouse to grow Raspberries?

There are some specific advantages to growing raspberries in a greenhouse over field grown berry’s. First, raspberries have a relatively low chilling requirement for over-wintering, about 45 days below 45°F. Then the plants can be brought into the greenhouse from the cold to bring them out of dormancy early. They also prefer cool growing temperatures (55°F to 70°F), so the cost of heating the greenhouse is less than it would be for other crops. Growers in areas that winter begins early, have the added advantage of satisfying the chilling requirements (over-wintering) earlier. Those in warmer claimants may find it beneficial to use a separate chilling room to speed up the process.

Also in most locations they don’t need supplemental lighting to produce high yields. One study did a test using both supplemental light and without. The plants with supplemental lighting began to flower 2 weeks earlier, but the total yield over the season (about 4 months) was just about even for both tests. Another advantage to growing raspberries in a greenhouse is that greenhouse plants are not subject to the foliage and berries getting wet by rain or dew. Wet raspberries are very susceptible to rotting, and damaged berries are useless and won’t sell. So just by using a greenhouse to grow them in, you will significantly increase the profitable/usable yield of your plants.

Greenhouse raspberry plants are typically watered via-drip system whether they are grown hydoponically or not. But growing them hydroponically significantly reduces the possibility of soil born diseases being introduced to the root systems, provided they were certified virus indexed plants to start with, resulting in healthier plants. Because the fruit has been kept dry (out of the rain and morning dew), the storage and shelf life of ripe raspberries (under refrigeration) is greatly increased, thus stays fresher longer for the consumer. In addition, many of the insects/pests that can be a problem during the summer months are not active during the off season in the cold winter months.

Growing your hydroponic Raspberries

Even with all the requirements that raspberry plants have (size, trellising, chilling etc.), they have been grown in practically all types of hydroponic growing systems, even NFT, DWC and Aeroponic. Some growers may even use grow bags full of growing medium, and simply cut a slit in the bag to insert the plants in and use a non recovery drip irrigation system. A well fed raspberry plant doesn’t necessarily have a large root system for it’s size, it can be even smaller than that of a mature tomato plant, but still last for years. As always hydroponic growing medium is mostly a personal choice, however it’s important to make sure the growing medium drains well and doesn’t remain to wet. Typical growing mediums used for raspberries by most growers include: sand, vermiculite, peat and perlite, either by themselves, in equal parts, or in just about any combination of them.

Probably the most common type of hydroponic system to grow raspberries in is a drip system. Either as a recovery ,or non-recovery system (also called run to waste). Non-recovery simply means that the nutrient solution is not returned back to a central reservoir, but is allowed to run off. Depending on the size and age of the plant, growers use buckets starting from 3 gallons and transplanting into larger buckets up to 7 gallons as they get bigger. All the plants energy is stored in the roots, so make sure to take care to do as little damage as possible to them when transplanting if doing so. Also make sure not to let the roots dry out before, during, or after transplanting.

To determine how many raspberry plants can fit in your greenhouse, just calculate how many plants you can fit in a row, spacing them two feet apart. For floricane-fruiting plants, determine how many rows you can have with about 5 1/2 to 6 feet between rows, remembering to leave at least 3 feet between the end rows and the greenhouse walls (for harvesting etc.). Rows for primocane-fruiting varieties can be spaced closer, at about four feet apart. Closer spacing can result in pour air circulation that can lead to disease.

Optimum Growing Conditions
Growing Raspberry plants using hydroponics gives the grower maximum control of the plants nutrition, and naturally quality. According to one study raspberries grow better with a higher proportion of N relative to P and K. Another study used the same nutrient formula they used for strawberries with very good results. Raspberry’s are a crop that can tolerate low light levels, and even lots of cloudy days. So even though supplemental lighting may increase a yield somewhat, the cost of running the lights may out-way any increase in yield from of using them. Not to mention, considering the add expense of installing them if they were specifically installed for the raspberry crops only.

Raspberries thrive in cool climates, with the optimal daytime temperatures around 72°F, and nighttime temps around 55°F to 60°F. But like any plant, they can tolerate and adapt to higher or lower temps, as well as fluctuations. The optimum humidity range is between 65% -75%. Humidity levels above 90% will encourage fruit molding and pour pollination. Humidity levels below 65% will encourage mite infestations as well as pour pollination also.

A supporting trellis system is an important part of good raspberry production. As the fruiting laterals become heavily weighted down with berry’s and foliage, they will tend to bend over and break from the weight. Once the growing season is over all the leaves can be trimmed off, and the old canes can be pruned off as well. Pruning and trellising will affect plant growth, fruit quality and quantity, as well as size. So you should get to know your canes.

Pollinating Raspberry’s

Unfortunately pollination is probably the biggest drawback to greenhouse and off season production of raspberries for most growers. Unlike some crops that can be pollinated by shaking the plants, air currents and a just a good breeze, raspberries need to be pollinated by insects. More than 30 flowers can be produced by one single fruiting lateral, and most buds that reach 2mm continue to develop, set fruit and mature. Insect pollination is essential for good fruit set. Hand pollination is to labor intensive, not to mention to hard to keep track of which flowers were pollinated to be cost effective.

For summertime crops, some greenhouses may be built with openings that allows outside bees to come inside to pollinate. But depending on the size of operation that may still be inadequate to pollinate all the flowers, although a beehive can be brought into the greenhouse for adequate pollination. For the home grower, planting flowering plants around openings in the greenhouse will attract bees inside to pollinate the raspberries. For off-season (wintertime) crops, most bee hives are inactive, especially in northern areas. Even inside a greenhouse it may not be warm enough for bees to be active enough, even above the optimal temp for raspberries of 72°F.

Bumblebees are very good pollinators, and remain active in much cooler temperatures than bees. They are also quite docile and wont sting unless provoked. But bumblebee hives don’t have a long life-span like bees do. Bumblebee hives will last about 10 to 12 weeks or so. Depending on the variety of raspberry and if your staggering 

 

the production cycle or not, you may need more than one bumblebee hive to pollinate your crops. The stigmas of the flowers may only remain receptive to pollination for about 6 days or so, so it’s important to have your pollinators ready when the flowers begin to open. For growers serious about raspberry production, it may be well worth their while to learn to raise bumblebees themselves, especially for year round production.

Along with bees and bumblebees as pollinators, Blue Bottle Fly’s are a recent option for pollination. Like bumblebees the blue bottle fly’s will remain active in cooler temperatures than bees will. Blue bottle fly’s are also suited for use in greenhouses. They don’t like to stay in one place, and tend to fly off. But work well in confined spaces like a greenhouse environments. It’s important to remember bees, bumblebees and fly’s are all insects also, the use of pesticides will have a negative effect on them as well. Most growers are learning that the use of beneficial insects for pest control will still allow them to be able to control the pest populations, as well as not effect the other beneficial insects like the important pollinating insects.

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Growing Hydroponic Raspberries, part 1

Typically raspberries are not considered good plants to grow hydroponically by growers because they are long term plants that depending on type of raspberry plant, may not produce any fruit in the first year. Because there are no real large producers of out of season raspberry’s in the USA, most of them are imported from Mexico and Chile during the off season. That results in pour quality as well as higher prices because of the long distance they have to travel get to market. Even with the high prices and low quality of off season raspberry’s, people are still apparently willing to spend their money on them. And for those people who like fresh raspberries, growing their own can be very rewarding.

Raspberry’s are a high value crop that can sell for between $3 and $6 for a 1/2 pint during the off season, and typically sell for around $3 or more when they are in season. Each plant can produce 8 to 11 1/2 pints of berry’s in one season (about 4 months) for second year plants,  and 3 or 4 year old plants can produce as much as 20 1′/2 pints or more in a season. Let say they sell at $3.50 for a 1/2 pint, and each plant yields 11, 1/2 pints, that’s a total of $38.50 (11, 1/2 pints at $4.50= $49.50) of product from each plant. So there’s a lot of potential for profit, especially when rotating plants to provide for both in and out of season berry’s. Even so very little information exists on hydroponically grow off season raspberry’s. Yet because they are a highly perishable product, there is always a demand for fresh locally grown high-quality raspberry’s.

Types of Raspberries
There are two basic types of raspberries plants (called canes). Primocane-fruiting (Fall-Bearing, and/or everbearing) and Floricane-fruiting (Summer-bearing). Primocane-fruiting, produces fruits at the top of the first year canes. If allowed to over-winter, these same canes will produce fruit again on the lower portions of the canes in early summer of the second year. However the second year fruit of the primocanes is said to be less quality than the first year fruit. Some growers will sacrifice the second-year crop in favor of the smaller but higher quality late fall primocane crops by pruning the canes to the ground, at either the end of the first years harvest or in early spring of the next year before they begin to grow again. Then new canes will continue to grow and fruit each year in late summer.

Floricane-fruiting (only produce fruit from buds on second-year canes), and unlike primocane-fruiting raspberries, these canes must stay intact through the winter and into the following growing season to fruit. Also, during second-year of floricane-fruiting raspberry plants, while the canes are flowering and fruiting new first-year canes are growing (also called primocanes because these are the first year canes). These will produce fruit in the fallowing second year. At the end of the harvest year the second year canes (floricanes) should be cut to make room for the new primocanes that will fruit the fallowing year. If not they will just die and not produce fruit anyway, taking energy away from the fruiting canes.

Advantages and Disadvantages
Primocane-fruiting Advantages

• long harvest season from the same plant
• less labor moving plants in and out of the greenhouse because of the long season
• higher density of plants can be placed in the same space
• only a simple trellis is required for support

Primocane-fruiting Disadvantages

• mites and other pests can build up during the longer harvest season
• bees must be active thought the long season for pollination
• Primocane plant yields are lower than floricane

Floricane-fruiting Advantages

• superior flavor and fruit size than primocane
• shorter harvest season, but with higher yields
• easy to schedule plant rotations for production cycles
• bees have a shorter season they need to be active
• pests easier to control because of shorter growing season

Floricane-fruiting Disadvantages

• larger plants so they take up more space
• plants require more trellising support than primocane
• plant requires more labor in manipulation of the canes
• it may be two years before the full potential yields are realized
• accumulation from the chilling is required to come out of dormancy

Raspberry cultivars
For some reason not all raspberry cultivars (variety of a plant) produce well in the greenhouse environment. Some of the varieties that have shown to do well in the greenhouse include: (primocane  varieties) Caroline, Josephine, Autumn Bliss, Autumn Britten, (Floricane  varieties) Tulameen, Chilliwack, Cascade Delight and Encore. The Tulameen variety seems to be a particular favorite for it’s large size as well as it’s flavor, and also seems to be particularly resistant to insects and disease.

Growers that want to grow raspberries for profit will want to obtain high quality virus indexed plants from a reputable source. Preferably from a nursery that sells certified virus indexed stock. Certified virus indexed raspberry stock is propagated from plants that have never been exposed to the outdoor environment. They are grown under very strict conditions in order to be free of pests and viruses, including soil born pests and pathogens. Field grown plants can be used, but are much more likely to introduce pests and disease into the greenhouse that can affect the entire crop. Also virus indexed raspberry plants generally grow more vigorously, as well as be more productive and even tend to live longer.

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Millions of dollars lost in hydroponic tomato plant sabotage

The search continues for the person or persons responsible for poisoning 7 million tomato seedlings, and nearly 16,000 tomato plants near Queensland, Australia. The 16,000 tomato plants were fruiting and about to be harvested when the poisoner struck, destroying 40 tonnes of produce. A numbers of capsicums, watermelons and eggplants were also killed as well. The saboteur poured an herbicide into the farms water supply. Two neighboring hydroponic farms were directly affected by the poisoning, Donnelly Farming (growers of hydroponic tomatoes), and Supa Seedlings (a large seedling grower). The poisoning of the water supply caused both farms to loose their entire crops. Even though only two farms were directly poisoned, the effects reach much farther, hurting about 30 of the areas 40 district’s farmers who had pre-ordered plants for planting and had them all wiped out. Many of the local growers rely on these seedlings for their plants. 

The Queensland area is the largest producer of fresh tomato’s in Australia, and supply’s major city markets like Sydney, Brisbane and Melbourne, along with many smaller markets. The region grows 80% of the Australia’s September tomatoes. And with such a large percentage of the nations fresh tomatoes coming the Queensland region, the sabotage is likely to have nationwide consequences, resulting in spiking supermarket prices. In 2005, Queensland produced nearly 86,000 tonnes of tomatoes worth about $90.6 million dollars.

 

But the cost to the region goes far beyond just the cost of the plants and rising tomato prices. Many farms that were expecting to be growing plants had to lay off workers, as well as company’s that expected to be picking, packaging, processing and even shipping the produce to markets were all heavily affected by the poisoning. The estimated cost to the region could climb to as much as $50 million dollars in reduced spending.

The Queensland’s Health department says that tomatoes from both of the property’s have been tested, and have been found safe for consumption. The tomato’s had no residue of herbicide that could be detected. They also said that they will continue to do testing for future crops. Although there are concerns about health implications because the poisoned water is also a part of their household water supplies as well.

Police are investigating the incident

The poisoning occurred in late June of 2010. Both of the affected properties use water from the same holding tank, and it’s been established that the herbicide was introduced into the water supply that both properties draw water from. Police are suspecting that the sabotage was an inside job because it had to have be done by someone with an intimate knowledge of irrigation systems. There are a lot of area farmers who have access to that creek, and a large number those farmers also draw water from the same creek as well. So it obviously had to have been done by someone that knew the area well, and how the pump systems worked. The saboteur/s snuck into the pumping station and injected a large amount of herbicide into a pipe system when the pump was engaged. From there the poisoned water went into the main lines that supply both of the property’s.

 

Police have little to go on, but say they are determined to find the culprit. They have assigned a team of 12 investigators to the investigation. They are also offering a $200,000 reward for information leading to the arrest and conviction of the perpetrators. It’s rumored that police are receiving numerous tips, but they aren’t saying if any of them are panning out. They don’t want to speculate but have said all along that it could be as simple as just plane vandalism to someone that has a grudge against the farm, and/or even a attempt to influence the competition or markets.

It’s also not the first time farms in this the area have been targeted, this is actually the third time crops in the region have been poisoned. In 2002, another Queensland Seedlings Nursery, just about a 10-minute drive east of where this year’s attack took place, was also targeted.  That time resulted in about $6 million dollars worth of losses in seedlings. And in July 2006, as much as $1 million dollars worth of crops were destroyed when a poison was put into the water tank of an aerial spraying contractor. Naturally with so much financial damage, and with so much pressure to find the culprit, there’s naturally a lot of anger, as well as finger pointing, gossip and rumors. Things have even gone so far for one man that has had his neighboring farm raided by police, that he has felt the need to hire a public relations firm to speak out in behalf of his innocence after receiving threats.

What’s the world coming to where anybody would want to devastate so many lives. I just cant imagen what’s going through their mind, or how they could even live with themselves after doing such a thing. The scary thing is how such a simple act of putting something in the water supply can cause so much damage, and put so many lives at risk. Not to mention how easy it is to do and go unnoticed. I guess we can all learn something from it though. There are people out their that have no conscience, and sadly that’s the reality. And with all the other things there is to worry about, we have that to worry about now too. Gone are the days where we could just trust people.

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Tips for getting the most out of your nutrients

With all the different brands of nutrients on the market today, the question always comes up, witch ones to get for the best performance? But growing good, productive, healthy plants is more complicated than just simply picking a good quality brand of nutrients for the type of plants you want to grow. There are a lot of good quality nutrients on the market. But the first thing growers typically blame is the nutrients if they wind up with poor plant performance. Then they usually just decide to try another brand, and go on another quest looking for the best one. But before changing brands, there are some things to consider before blaming the nutrients for causing the poor plant performance. 

First Tip
 

The first important factor is volume of your nutrient reservoir. That is deciding how many gallons of nutrient solution you need for each plant in the system, total in the reservoir. Larger plants use more nutrients and water than smaller plants do. So use your plants as a guide as to how much nutrient solution is needed to properly supply them with what they need. For instance for large plants like tomatoes you should estimate at least 2.5 gallons of nutrient solution per plant in the system. For medium size plants like peppers or basil estimate at least 1.5 gallons of nutrient solution per plant in the system. Then for smaller plants like strawberries or lettuce estimate at least 1/2 gallon of nutrient solution per plant in the system. Then multiply that by how many plants you plan to grow in order to give you a minimum reservoir size.

This is important because larger volumes of nutrient solution will have smaller fluctuations in their nutrient concentrations as the plants use them up. Basically this helps keep the nutrient solution evenly balanced as the plants deplete the nutrients from it. Also in warm/hot weather the plants transpire (use) more water than they 

do in cool weather. As the plants use up more of the water from the reservoir than usual, this concentrates the nutrients (EC levels) that are left in the solution. With smaller water volumes there is a much better chance of nutrient levels soaring to toxic levels/concentrations. Even when regularly topping off with fresh water to the original volume in smaller reservoirs, there is a lot of fluctuation of the nutrient concentrations that wont do your plants any good.

Second Tip
 

There are a lot of variables that can affect the amount of nutrients the manufacture recommends to use (dosage). Of coarse some trial and error here can be helpful to you in the long run, but you should start with what the manufacturer recommends. After all, they know their nutrients best. Some of the things that can affect the dosage that the nutrient manufacturer recommends to use are plants size (seedlings, small plants, heavy growth etc.), the plants growth phase (like vegetative growth or flowering/fruiting growth), type of growing medium (clay pellets, Coco cor, Perlite, Vermiculite etc.).

Even the type of system like recirculating or non-recirculating systems can make a difference. Most manufactures assume that your plants are going to be grown in favorable conditions, so they don’t always post directions for weather extremes for those people that grow outdoors. But like I mentioned earlier, the plants will take up more water in hot environments, and going a little under the recommendations (dosage) for hot conditions is generally recommended.

Third Tip
 

When mixing your nutrients and/or additives, add all the water (at least 3/4 of it) to the reservoir first. Two and three part nutrients are separated for a reason. If you pre mix them in concentrated form or even small amounts of water first, some of the elements in the solution that were separated now have a chance to bond, and a white precipitate (calcium sulphate) may even be seen forming in the solution. By thoroughly mixing each concentrated part of the nutrient (and/or additives) one at a time into the larger volume of water will keep them diluted enough so they wont have a chance to bond together. If they do, they will become un-usable to the plants.

Forth tip
 

Keep your nutrients mixed up. For most systems this wont be much of a problem, using a air bubbler in the reservoir will easily keep the water moving. Also most systems that recirculate the nutrient solution should also keep the water mixed up enough. This keeps the mineral elements from settling and concentrating at the bottom. This also prevents areas/pockets of high or low pH levels, where the mineral elements then become unusable outside of the plants pH range.

Fifth Tip
 

Check your pH often. Plants are only able to uptake the nutrients in the solution if the pH is in the right range. After mixing your nutrients immediately check the pH, and adjust it if necessary. Then recheck it until it’s right. After that checking it daily would be recommended. Letting the pH go out of range will deprive your plants of nutrients, and allowing pH to rise above 6.5 can often cause the white precipitate to be seen in nutrient reservoirs also.

Conclusion

It’s not just having good nutrients that maters, it’s also how you use them that makes the most difference in their performance. By taking the time to regularly fallow a few basic guidelines, as well as checking the manufactures instructions, then fallowing their instructions correctly. You will be able to get the most out of any nutrients you choose to use. Growing good hydroponic plants requires a little more work than just pouring some water on a mound of dirt, but well worth the effort.

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