AHH. Here we grow... I just need an extra $20, 000 to get a few itemm ,,, no problem.. :
If you’re lucky enough to have an unlimited budget when setting up a high-tech greenhouse, you’ll want to consider the following items:
- Multi-sensor quantum light meter— Many light meters used by small growers only measure in foot candles or lux, both of which are not particularly useful when it comes to plant usable radiation, or PAR (photosynthetically active radiation). No point measuring light that the plants can’t use. Quantum sensors measure light energy in the specific wavelengths that plants actually use for photosynthesis, and so give a much more accurate reading of what useful light is being provided naturally and/or artificially with grow lamps. Meters with a sensor bar attached are the best option as light can be more accurately determined in different positions within the plant canopy. A multi-sensory quantum light meter is ideal for small or large hydroponics growers.
- Chlorophyll meter— Chlorophyll meters are another useful tool and fun gadget for giving an indication of plant health and stress before growth becomes adversely affected. There are a number of models of chlorophyll meters on the market, from some quite simple versions to the high-tech, integrated data-logging model. Chlorophyll content is instantly measured by clamping the sensor over a leaf and receiving an indexed chlorophyll content reading. The Minolta SPAF 502 DL meter is one of the most advanced chlorophyll meters on the market. It’s not only a useful crop-diagnostic tool, but also a great learning tool for classroom experiments and student projects.
- Individual nutrient element meters (Cardy) or complete onsite nutrient analysis systems (Merck)— There are a few different individual nutrient element measurement systems on the market. However, for the hydroponic grower who wants a quick, accurate and simple to use analysis system, the Cardy element meters are a good choice. These small pocket-sized meters can measure nitrate, potassium or sodium quickly and easily, so are great for basic nutrient analysis. Cardy plant nutrient meters are particularly useful for those who might be growing fruiting crops and need to measure the nitrate-to-potassium ratio and levels on a daily basis. Also, for growers who battle sodium in the water supply, a quick check with the Cardy sodium meter will determine when levels of sodium have accumulated in recirculating hydroponic systems and determine when solution dumping is required.
For a more complete and advanced nutrient analysis system, Merck Ltd. has a selection of element analysis systems designed for agricultural, water-based systems, aquaculture, food production and hydroponics. The Merck Reflectoquant system is a remission photometer (RQflex) that uses individual element test strips for evaluation of nutrient levels. A major advantage of the RQflex for hydroponic growers is that all of the macro-nutrients and many of the trace elements be tested with this system. It can also be used to determine pH, chlorine and peroxide levels in solution. This is great for growers who use hydrogen peroxide or chlorine in their systems for sterilization purposes, because dangerously high residues could damage sensitive crops. The Merck Reflectoquant can also be used in product-quality determination as one of its major applications is in the food-processing industry. Ascorbic acid (vitamin C), glucose, acidity, pH, malic acid, and others can be assessed in fruit and vegetable samples, giving growers a good option for quality assessment from their hydroponic crops. Also, the system can be used for soil samples, media samples, analysis of fertilizer as well as standard hydroponic nutrient solution testing and checking. This system of analysis is well worth the investment as instant results with nutrient composition can be obtained—no waiting two weeks for the lab to return analysis results. Rapid nutrient readings are invaluable to any hydroponic grower when a delay in nutrient adjustment could lead to crop failure.
- Complete water quality analysis system— good water quality is vital for any hydroponic system. However, water parameters tend to change over time and need regular testing and assessment. Hydroponic operations can also make good use of water analysis systems that measure dissolved oxygen—an important aspect affecting crop health and productivity. The U-10 water quality analysis, available from Spectrum Technologies, gives highly accurate, on-site water testing, measuring pH, temperature, dissolved oxygen, electrolytic conductivity, turbidity, and salinity. Applications for hydroponic producers not only include solution testing and water supply evaluation but also checking the parameters of waste water, solution drainage, aquaponic tank systems and any other water source involved in the hydroponic production system. The unit is also portable and waterproof, important options for hydroponic growers.
- DO meter— Unlimited budgets would allow for maximum use of monitoring equipment, and a dissolved oxygen meter is a tool all commercial growers should have. However, in systems such as NFT, pond or raft setups, having multiple sensors placed around the production system becomes the ultimate in monitoring and control. As with EC, ppm and pH meters, dissolved oxygen meters have come a long way since the early days of large, lab-based machines. Now, oxygen can be measured in situ, which is important since the DO levels can be influenced by taking samples and transporting these to a lab for measurement. Hydroponic systems do allow very accurate measurement of dissolved oxygen in solution—either at the nutrient reservoir or around the production system, even in the root zone of many systems. Hand-held, easy to operate and highly accurate dissolved oxygen meters not only measure DO but also percentage saturation at the current temperature of the solution being measured, a useful tool for growers who need to measure and improve the degree of oxygenation in their hydroponics system. Even small hobbyist growers can find a use for DO meters to check and adjust their aeration methods for maximum plant benefit. There are many excellent DO meters on the market. Hanna Instruments has a waterproof meter—HI9142—that’s well suited to hydroponic applications and certainly worth the investment.
- Meter for measuring pH in solution and in media— There are plenty of well-designed, waterproof and accurate pH meters available for hydroponic applications. While these are well suited to NFT and other solution-culture growers, those with media systems often find them less useful. pH levels in the root zone of media-grown crops are important as they effect nutrient availability for plant uptake and need to be maintained within a certain range. While it is possible to create a liquid media extract or to collect solution leachate, should there be any, these are not always totally representative of what might be occurring in the root zone. The IQ 150 pH meter from Spectrum Technologies allows for pH measurement in soil, media and water/nutrient solutions. The probe on this meter can be used to measure pH directly in the growing media on site, giving instant readings of pH levels in the root zone as well as those in the nutrient solution and water supply.
- MiScope Digital IMP Camera and Macroscope— Here’s a really great toy for classroom hydroponics and science fair projects, as well as any grower who likes to focus on the finer details—a digital microscope that fits in the palm of your hand. Macroscopes have been round for quite a while and are commonly used for magnifying small insect pests, plant disease symptoms and other plant disorders. The MiScope Digital IMP Camera and Macroscope goes one step further and combines a digital movie camera, built in LED lighting and precision options in a small hand-held microscope. This gives 40—140x magnification so the finer details of tiny insect pests and the leaf surface can be easily seen up on the computer screen and then captured as images or movies for later viewing. The IPM Scope connects to a computer USB port and is ideal for teaching or staff training operations out in the greenhouse with use of a laptop. Identification of many crop pests, disease symptoms and beneficial insects becomes an easier process as many people can view the footage in either real time or as recorded files in large format on the computer screen.
- Pocket digital refractometer— Refractometers are another instrument that has been in horticultural use for a long time. Hand-held brix, or total soluble solids, meters are most commonly used in the wine industry to determine when sugar levels in grapes are high enough for harvest. However, many other industries also use refractometers to gauge crop maturity, food quality and other aspects. They are one of the most useful tools for fruit and vegetable assessment if used correctly. For the unlimited budget there is even an attractive new digital hand-held refractometer that fits in your pocket. Brix is a reliable measure of product quality and, in particular, eating quality or flavor (sweetness) in many common hydroponic crops such as tomatoes, strawberries, capsicum, melons, and many others. It’s a tool that producers should know how to use. The problem with the old manual brix meters has always been the scale, which needs to be read by eye, and it can be difficult to get a high degree of accuracy between samples that are relatively close in brix levels. The digital refractometer has an accuracy of 0.2% and measures in increments of 0.1%. New digital hand-held refractometer measures accurately (± 0.2%) with a scale of 0-53% and fits in your pocket. It also has automatic temperature compensation and a large digital display and can obtain readings from minute samples via a special sensor unit. This is a must-have tool for hydroponic growers who like to regularly assess the quality of their crop or compare samples from within a crop.
- Infrared thermometer— Infrared thermometers are in widespread use in the food industry. For example, infrared thermometers are used to gauge food temperatures to ensure proper storage. They also have many applications for hydroponic use, and unlike many of the smaller techno gadgets, they won’t break the bank. Infrared thermometers operate by shining an infrared beam of light onto the surface of an object—the temperature of the surface is then recorded and displayed in either Fahrenheit or Celsius on the meter’s digital display.
Leaf, or canopy, temperature usually differs from air temperature, and so should be checked, particularly under warm or high-light conditions. Plant leaves transpire, cooling them in the process. A healthy, activity photosynthesizing crop will have leaf temperature close to that of the air temperature. A crop that has shut down and closed the stomata will have a leaf temperature above that of the air temperature and eventually it will begin to wilt. The objective of measuring leaf temperature is to assess plant stress and prevent problems with plants shutting down during the course of the day due to heat, humidity problems or other disorders.
Infrared readings can also be taken of the nutrient solution at any point in a hydroponic system and are also great for checking solution temperatures in NFT channels, pond, raft systems or nutrient tanks. Their other important use for infrared meters is during post-harvest handling and storage to gauge temperature reductions after harvest.
- Dew point/temp/RH meter—While most high tech greenhouse set up on an unlimited budget will have all the sensors and monitors available, its still nice to have a few hand held gadgets for extra spot checks inside the crop. The portable Thermo-hydrometer with dew point is a hand held meter that displays temperature and temperature compensated humidity readings side by side. A digital sling Psychrometer unit is also available (3411WB) from Spectrum Technologies which gives a measurement of wet bulb temperatures. For growers experiencing humidity and resultant disease outbreaks such as botrytis in certain areas of a greenhouse or crop, this is a useful tool for determining where humid areas form so that adjustments in heating and air movement can be carried out for disease prevention.
- Hanna portable, printing and loggin pH/ORP meters— Hanna Instruments has long been a manufacturer of some of the best electronic meters for hydroponics. Nowadays growers can select from a larger range of “combo” meters which are great for measuring a number of important variables in the nutrient solution. As an added bonus, some of the Hanna products also have printing and logging functions for data collection. The Hanna HI 98230 and HI 98240 pH meters are a step up in the pH meter department—they have a built in plain paper printer, so no more scribbling down pH readings or relying on memory. It also has logging and log on demand features so data can also be stored for later access and downloading to a PC. These meters also come with an internal temperature sensor, buffers and electrode cleaning solution—all the necessities for accurate pH measurement in hydroponic systems.
- Combination meters—Many meters manufacturers offer a huge range of “combo” meters, with most growers these days having at least EC and pH combined on the same meter, if not more parameters for nutrient solution assessment. The advantage of these meters are their long life, accuracy and being waterproof also helps for the accidental splashes. With more and more parameters being offered on the single meter, a good choice are the meters which integrate EC, ppm, pH and temperature of which there are a number of models. To go one step further, the Hanna HI9835 waterproof, auto ranging, EC/TDS/NaCl/ and temperature meter is a great tool for hydroponic growers, particularly those who like to monitor salinity build up in their systems or are dealing with saline water sources. These meters also feature automatic calibration and battery consumption displays with a single probe for all measurements and a large LCD screen for display of all readings.
You’ve outfitted your high-tech hydroponic greenhouse with nothing but the best equipment money can buy. You’ve every reason to expect your investment to yield improvements in crop growth, productivity and quality. But there’s still one missing ingredient: knowledge. You’ll need to learn as much as possible about hydroponics and horticulture if you’re to make good decisions based on the reams of data you’ll now have at your fingertips.
One of the best and easiest ways to add to your knowledge is buying and reading books and magazines about hydroponics, such as Growing Edge. Another good way is by taking an advanced course in hydroponic greenhouse design, controlled environment agriculture and hydroponic production.
Dr. Lynette Morgan is a regular contributor to The Growing Edge. She holds a Ph.D. in Vegetable Production from Massey University, New Zealand.
For the complete version of this article, see The Growing Edge,
Volume 17, Number 1, September/October 2005, page 26.
