Hydroponic Chronicles

About the Book

This book will focus on improving marijuana through the use of Indoor hydroponics. The techniques mentioned in this book are for the medicinal uses of cannabis and for those legally able to grow it. 

Indoor-Hydroponic gardening is a lot like building a house, you have all the necessary supplies to build the house: wood, nails, brick mortar and equipment.  You have your blue prints, but this does not make a house.  It makes a pile of rubbish.  You have to put the supplies together in the correct order with skilled labor in order to end up with a house. In a sense, this is what Indoor-Hydroponic gardening is like.  You must know how to properly utilize your supplies and equipment-this is what a guide like this is for! It enables you to finish with a house instead of a pile of rubbish.

If you are new to Hydroponics here is what wiki-pedia has to say-

“Hydroponics (from the Greek words hydro (water) and ponos (labour)) is a method of growing plants using mineral nutrient solutions instead of soil. Terrestrial plants may be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel or mineral wool. A variety of techniques exist.

Plant physiology researchers discovered in the 19th century that plants absorb essential mineral nutrients as inorganic ions in water. In natural conditions, soil acts as a mineral nutrient reservoir but the soil itself is not essential to plant growth. When the mineral nutrients in the soil dissolve in water, plant roots are able to absorb them. When the required mineral nutrients are introduced into a plant’s water supply artificially, soil is no longer required for the plant to thrive. Almost any terrestrial plant will grow with hydroponics, but some will do better than others. It is also very easy to do; the activity is often undertaken by very young children with such plants as watercress. Hydroponics is also a standard technique in biology research and teaching and a popular hobby.

The FIM Technique

Another way to supercrop is called the FIM technique.  This method is used to produce more growing shoots and simultaneously keep the plant bushy. It involves cutting off 85% of the growing shoot and leaving 15% intact. From the remaining 15%, up to 6 branches emerge. This is due to the rapidly dividing cells of the shoot that grow in every direction.  The purpose of this technique is, again, to slow down vertical growth, but also to produce more branches for budding.

How to Increase the THC Content Using Light

For a traditional cropper, Grower-X sure does a lot of experimenting with Indoor lighting.  Among his favorite ads is the black light.  He has tried many different techniques, timing and combinations, with this light source. He has found that a black light can be utilized best in small amounts once or twice daily. He explained to us that if you bombard the plants with ultraviolet “photons”, it will cause the cannabis to produce more THC.  The plant actually is attempting to protect itself from the harmful rays, and it just so happens that THC is it sunscreen. He was quick to point out, “this should only be done during the flowering stage“, and that this light source should be used in conjunction with your normal light source(s).  In his experience he has found that the plants should only be exposed to this light in three intervals, of ten minutes, with a thirty-minute rest in between each interval, at a maximum of thirty minutes a day.  If it is used any more than thirty minutes a day it could damage the plants.

Stages of Growth

It is exceedingly important to be acquainted with the various stages of growth for the marijuana plant-particularly if you are attempting to grow in an Indoor-Hydroponic garden. Environmental needs will change as the plant(s) develop- predominantly with regard to lighting and nutrient supply at first.

Vegetative growth

After the plant has sprouted, it begins the vegetative growth stage. This is when the plants energy is focused on growing the plant in height and width. All plants have a vegetative stage. And, it is this stage that can predetermine the plants future health. If you do not nourish your plants appropriately; or do not supply the plants with the correct amount of light- You could cause your plants to develop in such a weak manner, that they would be real susceptible to disease or wilting in the future. As plants enter the vegetative stage the concentration of the solution is increased, which increases the amount of nitrogen. The plants are kept on a high N nutrient solution until you begin flowering (see nutrient section).

For the duration of this stage the plants grow with little or no dark period. The constant light increases the speed, at which they grow, by 20-30%. The lights should be on endlessly because the plants do not require a dark period, until they reach flowering. So make an effort to keep lights on for a minimum of 18 hours per day.

During the premature stages of vegetative growth you should bend the plant’s stems back and forth, in a slight side to side motion, to force the stems to develop stability and strength. Weak stems will not support heavy flowering and usually bend as a result. An oscillating fan, pointed directly at the plants, will help improve stem strength as well.

Flowering

A plant begins to fruit or flower when dark cycles of between 10-13 hours are introduced. The only special requirement during this stage is to keep the dark period dark, with no light interruptions.

Dark periods are mandatory for cannabis plants to flower. Plants will seldom flower if they are exposed to consistent light. Flowering requires lamps to be on a timed sequence that generates a regular, strict, dark period. After three weeks of strict dark periods, the schedule can be relaxed a little because the flowering stage, by this time, has already begun and there is no going back.

It is important that during the

FLOWERING PHASE

The dark period schedule should not be interrupted. Due to hormones in the plant that react to light you will delay flower development if it becomes intermittent. A green light should be used if it is necessary to work in the garden during the dark period. It will have no damaging effect on the plants. All of this notwithstanding, too avoid entering the grow room during dark periods-set the timers to turn off when you would normally not enter the garden.Flowering plants should be kept on a strict light regimen of 12 hours a day, after the initial three weeks (discussed above)-on average of one to two weeks.

Ostensibly, longer dark periods will speed the maturity of the flowers, but should only be used toward the end of the flowering cycle because introducing long dark periods too soon can make the flowers grow into underdeveloped buds. Consequently, if you choose to exploit the expedience of longer dark periods it will decrease the yield by a small amount.

Flowering plants like high P level foods, such as 5-50-17, or 10-20-10. Nutrients should be provided with each watering and old nutrients should be removed and replaced with new. Trace elements are necessary too: try to find nutrients that contain them; so you don’t have to add a separate trace element compound.

Flowering plants should not be sprayed with anything water based, otherwise, you could promote mold. Keep humidity levels indoors low when flowering to avoid any mold development while flowering.

When

A plant is ample enough to flower at a height of 12″ or over, or around a total of 100 days of vegetative growing. Flowering is usually detected 1-2 weeks

The Hydroponic Bible

after a dark period has been introduced. If you see white hairs emerging from between its internodes, it has begun to flower. Moreover, white hairs confirm the plant(s) is female.

Three to weeks after the dark period is introduced, your plants should be covered with white pistils emerging from every grow tip, assuming they are all female of course. These are the flowers- the beginning of the almighty girl, the bud! When you want the flowers to mature after your regiment of twelve hours a day- you need to turn the lights back to 7-10 hours a day.

The plants will ripen, and should be ready to harvest in 2-4 weeks. Wait for the white hairs to turn red, orange, or brown. And, the false seed pods to bloat with resin or seeds. When 80 % of the pistils have turned color the flowers are ripe and ready to be harvested

Sex Determination

Marijuana is a genus of plant that reproduces sexually, which means the plant has male and female counter parts. The male plant develops pollen -essentially the same as human sperm. The female on the other hand, produces buds that contain tiny sacs which await pollenazation from the male. If the sacs are pollinated, seeds will develop. If the female buds are not pollinated then the sacs jam with potent THC molecules.

Most people promote crops that are entirely female, and do not produce seeds. To facilitate this you must first identify and remove all male plants. So the question arises, how do I determine the gender of the plant? Although we touched base on this in the previous chapter we must go over it in detail here.

You can ascertain the sex of each plant approximately two weeks after you begin to force the plants to flower. After two weeks on the flowering cycle, when the first flowers of male and female become visible, you need to identify the differences between the two. To distinguish between the two, look for the male flowers which are identified by small round pods hanging below the major internodes of the leaves. The females’ flowers grow in small clusters of leaves-with small white pistols sticking protruding from them. These pistols are the sticky receptors for the pollen.

After you have identified the males, gently remove them from your garden and dispose of them, or place them in another grow room if you plan to breed your plants. Be careful not to shake the male plants while relocating them because you could break open the pollen sacs, which will pollinate your plants and cause the females to become saturated with seeds. If you let your male and female plants grow together you will produce seeds, it is inevitable.

The Hydroponic Bible

Nutrient Monitoring Daily Check list:

To make certain your plants getting the proper nutrients and concentrations, check your nutrient solution daily with the checklist below.  Make sure all readings fall within the suggested ranges.

1.  Nutrient concentrations

2.  pH

3.  Temperature of solution

Watch Your Water

Mature plants process a surprisingly large amount of water. For instance, a fully-grown cannabis plant may consume up to a gallon of water a day. An inadequate water supply can limit the plants growth. Water deficiencies can cause the plant to focus all its available energy on developing an extensive root system to absorb whatever water is available.  This will result in a small, weak cannabis plant.  It is very essential to pay close attention to water levels; they need to be checked daily.

Types of Water

In preceding blog we discussed nutrients and its importance. The next step, it might appear, should be to discuss pH . However for seasoned croppers there is intermediate step, choosing water type. If you can, avoid using tap water because it has chlorine in it, which will causes your crop to harden. .  Distilled water works great; it has no added chemicals and does not contain any elements that can interfere with a solution. (Never use fluorinated water.) 

When using tap water, always use the water from your cold water pipe never the hot water.  Hot water pipes contain a lot more calcium build up in it than cold pipes, and your nutrient solution usually provides all calcium your plants need.  Water from a hot water line will create a solution imbalance, which can poison your plants.  Do not worry about your calcium levels becoming toxic if you use the cold tap water- it probably will not happen unless you have extremely hard water. 

Why do you need to determine whether you have hard water or not?  It is simple, hard water causes a build up of those trace elements we mentioned earlier, which cause fluctuations in your nutrient solutions. It is possible to identify this problem relatively easy.  Usually the pH of the water will be slightly basic, without any additives.  The most vexing problem with hard water, however, is how basic it is. Usually large amounts of acid are needed to balance the pH.  We recommend you purchase twice as much acid as base when using hard water. 

Soft water on the other hand lacks the abundant amount of salts necessary to cause a build up.  To identify soft water, deduce whether or not you have hard water.  If you do not, then you have soft water.  Soft water does not present any real problems; in fact, it is the same as buying water at the store (for our use any way). 

If you only have a relatively small number of plants we recommend you add small amounts mineral water, to the distilled, or tap water.  This type of water contains important trace elements that help plant growth.  It also contains bicarbonate, which is a great source of CO₂.  This type of water should only be used in small proportions, and in conjunction with another type of water- preferably distilled water.  You should mix the two types of water in a fifty-fifty mixture.

Foliar Feeding

Foliar feeding is one of the easiest ways to increase both yield and quality.  It is the process of feeding the plant through its vegetative growth-the leaves, stems etc…  It can be used in conjunction with, or without CO₂, and should be used in conjunction with root feeding.

How and When

The best time to Foliar feed is right before you turn your lights on, or three hours after you turn them off. The stomata of the leaves are wide open at this time and allow for better absorption of nutrients.  The temperature should be about 72 degrees. If the temperature reaches over 80 the stomata’s will close and the plant will not absorb the nutrients properly. A sprayer or mister should be used to convert the solution to a very fine mist.  Make sure the pH is normal, just like any other solution 6-6.3. A wetting agent should be used to prevent the nutrients from beading up, and burning the leaves.

Foliar feeding is also used as good way to get nutrients to the plant when nutrient lockup problems occur where the nutrient intake from the roots is hindered.

WARNING: It is important to wash leaves that are harvested before they  are dried.

pH

           pH is a measure of free-floating hydrogen (H+) ions in any solution and is the measure of  the acidity of the solution .  The complete opposite of pH is pOH, or amount of hydroxide ions (OH-) in a solution and is the measure of the solutions alkalinity.    A high level of OH- means the solution is basic, and a high concentration of H+ molecules makes the solution is acidic.  The scale of pH ranges from 0 (very acidic) to 14 (very basic) with 7 being neutral.   If the pH of your solution increases in number from six to seven it is read as a decreased in acidity.  Likewise, if your solution decreases from six to five the acidity of your solution just increased.

In hydroponics it is important to maintain a relatively constant pH.  You do not want too much fluctuation in the measurement of the pH. For example, one day your pH is measured to be 5.0 and two days later it some how moved to 8.0.  To keep your solution stable it is important to understand some guidelines.  First, you need to keep your solution moving with a circulatory pump.  Second, you need to exchange old solution for a new solution every week or two. This means all of the solution.  Third, your solution must be aerated.

It is necessary to keep the pH of the solution between 5.5 and 6.5 for cannabis.  Although it is our understanding, that cannabis prefers a constant pH of 6.0 a slightly acidic solution, but not acidic enough to harm the plant. A pH of 6 is ideal because it allows the roots absorb nutrients from the water.

To adjust the pH we recommend buying pH raise and pH lower from your local hydroponics shop or from a commercial manufacturer.  However, they are other methods to adjust the pH.  For instance, if you want to lower your pH in number from say 8 to 6 ( known as rising pH), all you have to do is add two tablets of aspirin per gallon of distilled water that are added to your system. 

To raise your pH in number say from 6-8 (known as lowering pH) you can add potassium hydroxide to the solution.  Typically it takes a very small amount per gallon to have the opposite effect of the aspirin.  It is necessary, about every two days, to check the pH. On average a plant consumes about one gallon of water a day, which will cause the pH to become more acidic.

The easier and more controlled method of adjusting the pH level is to use a premixed chemical adjuster.  These adjusters can be purchased at any hydroponic outlet and come in two bottles labeled pH raise and pH lower. To use this product you need to get a five-gallon bucket and add the new nutrient solution.  After that you check the pH of that specific solution.  Then using either pH raise or pH lower, you adjust the pH to the correct level. Remember to take a final pH reading before placing the solution anywhere near your plants

Why Dose pH Matter

Why does pH matter? The correct pH is essential to a plant because it is what determines, how, and if the plant absorbs nutrients. If your solution is either to acidic or to basic then your plants will not be able to take up nutrients appropriately.  The nutrients will precipitate into insoluble salts, and the plants will not be able to extract them from the solution.  This will cause your plants to show signs of deficiencies.  Moreover, very high or low pH levels can damage the plants vital root system, and burn its tissues.  If your pH falls below 3.8 your plant will start to show signs of potassium and calcium deficiencies.  If your pH rises to above 7.4 it will cause nutrients like iron to precipitate out of the solution, producing an iron deficiency in the plants. Basically if your plants start to change colors then you need to check, adjust, or change your solution.

How to Measure pH

The cheapest and simplest way to measure pH is to by the liquid measuring devices that use a vial of solution and a sample of water to measure pH.  You can find these at any Hydroponic shop.  The sample of water changes color when the solution and a chemical agent are added together in the vial.  It is compared to a color chart, which gives you a pH measurement that corresponds to the color of the mixture.

pH meter

The easiest way, to measure pH, is to obtain an electronic pH meter- this instrument does everything by itself and displays the reading on a digital display that is accurate to the decimal place.  In general, to use this device you simply turn it on and wait until the meter reads zero.  Then place the electronic tip in the solution.  It will then give you the exact pH reading of that solution

Limiting Growth Factors

          At some point you may make the observation that your plants are not up to expectation, or they simply have problems.  This is usually due to a limitation of certain growth factors. Usually these problems are easy to solve, and even easier to recognize. 

Water

Light Deprivation

Nutrient Strength
Nutrient Lockup
Light Spectrum
pH 
Low Temperatures

Temperature

Temperature is a key component to any successful garden.  The range of temperature has a direct affect on your plants growth rate and overall health, not an indirect one. If the plant gets to hot, or to cold, it could die- or become seriously ill.  Of course it is important to keep your grow rooms’ temperature at a constant, unvarying, optimum degree. 

Most cannabis plants originated from tropical climates, where temperatures rage between 75 and 90 degrees Fahrenheit. For this reason, the cannabis plant cannot withstand dramatic changes in temperature; it is best to keep your temperature consistently around 75 to 85 degrees.  Plants prefer higher temperatures, but do not under any circumstances exceed any temperature above 90 degrees Fahrenheit. If you exceed 90 degrees you risk damaging or destroying your plants, permanently. In contrast, if the temperature falls below the minimum, sixty degrees, your plants will go into shock, and could either die or begin to flower early.

Vegetative Growth

The reason for the high temperature during vegetative growth, and not flowering, is the high temperatures can dramatically reduce the potency of your buds during flowering because heat can shatter THC chemical bonds.  Adversely, high temperatures create humidity. Nevertheless, humidity caused by high temperatures, in moderation, increases the plants ability to take carbon dioxide-this allows the plants to grow faster and fuller.

Preparation for Flowering

When you want to begin Flowering it is a good idea to reduce the temperature to about ten degrees below the initial temperature.  This will trick the plant into readying for winter, which jolts the plant into species survival mode.   This mode basically tells the plant to hurry up and prepare to make seeds.  Hence, buds begin to develop hastily

Measuring the Temperature

It is important to always have a thermometer, along with a humidistat inside your grow room, so you can detect any fluctuation in the temperature or humidity. These dissimilar kinds of equipment go hand and hand.  One environmental change, in either the humidity, or temperature, will directly affect the other

To provide the right thermal environment you need to understand heat and the correct method to measure it. The temperature of a grow room can be divided into two distinct, aspects air temperature, and radiant temp…

Air Temperature:

In this blog when we discuss temp we are talking about the air temp.  A mercury bulb or digital thermometer is used to measure the temperature of air.  To measure the air temperature you place the measuring device in the middle of the grow room, and hold it away from the light or shield it from the light source.

Breeding

There may come a point in time that you choose to produce seeds.  This is usually done save them for future use. Sometimes people simply want to try a fresh strain and do not want to use cloned replicas of previous plants for one reason or another.  In order to do this people must breed their plants. With the right breeding method, it is possible to breed plants that grow, flower and mature faster than the parental plants.  It’s best to use plants that already naturally exhibit these extraordinary traits.    For example, it is best to pair off a fast maturing plant with a highly potent one to obtain both qualities of the parental plants.

Radiant Temperature:

 
Radiant temperature is the measure of heat transfer between real objects with different temperatures.  Cannabis plants will always be at a lower temperature than the lights above because heat is transferred to the plants, from the light source, and as heat travels it decreases in temperature. The leaves absorb heat, and the radiant temperature is increased between the two. If the is radiant temp becomes too high the plants burn and wilt. At first, burned leaves look pale green foliage that resembles an Mg deficiency.  The later stages of burn, turns leafs yellow and finally brown.

To see if your radiant temperature is too hot, simply place your hand next to the leaves of the plant.  If your hand becomes very hot, then the radiant temp is too high and the lights are too close to the foliage-they need to be adjusted

Regulating Temperature

Ventilation is the key to regulating temperature; you must harmonize your ventilation system with your lights, and counter-synchronize it with your carbon dioxide system.  The basic idea is while the carbon dioxide system is off, the ventilation system vents to reduce the temperature. As discussed in a previous chapter, it should vent the whole room in ten minutes. In addition, it is best to remove the excess heat hurriedly because it saves electricity

Controllers

Some atmospheric controllers that help regulate the temperature are Cooling Thermostat/Dehumidifying Humidistat, Microclimate Controllers, Total Humidity Controllers.

What to Do About Changes in Temperature

Salvation may be with in your grasp, depending how quickly you catch your mistake, and react.  Cannabis growers should understand that it is O.K. to let the temperature drop a little during vegetation growth, about five degrees at night.  It will not harm your plants.  In fact, this actually helps your plants, by allowing the substances produced by photosynthesis (sugars and starches) to move throughout the plant swiftly. Ergo, if you want your plants to grow more rapidly during vegetative growth it is a prolific idea to keep the temperature between 80-85 degrees F, and then allow the temperature to decrease five degrees at night.  Commit to memory- this is done only during vegetative growth, and not during flowering.

Water Temperature

So far we have explored the effects of temperature on flowering, on vegetative growth but we have not tackled the effects of the temperature of the solution on the root system; which is, in fact, an important aspect of overall plant health. The water should remain at room temperature, or between 75 and 80 degrees.  Thus it is important to have an aquarium thermometer for the nutrient solution.  The nutrient solution that is running, dripping or falling on your plants should be about room temperature.  We suggest that if you live somewhere that is cold; you get an aquarium warmer, or something that will keep the temperature around 75 to 80 degrees.   If for some reason the temperature should drop dramatically toward the fifties-then you should immediately find some way to adjust your temperature before the plants go into an irreversible shock and die.  If necessary, place the heater in your reservoir on a setting of low.

An increase in water temperature could also harm your roots but this only happens if you use a heater.  To fix this problem simply adjust the heater.

Odor Control

There are many products available to control, or reduce, the aroma of un-cultivated cannabis.  The most commonly used are ionizers, ozone generators, air scrubbers and chemical sprays.  None of these products (with the exception of Ozone Generators) will completely eliminate all of the pungent smell, but they will prevent it from saturating rooms outside of the grow area.

Ionizers

Ionizer’s work by generating negatively charged ions that are released into the air. When these negative ions come in contact with positively charged particles (the smell), the particles change to a negative charge, causing the particles to “precipitate”, or to fall to the ground. This produces dust on the growing room floor, but kills the smell

Air Scrubbers

Air scrubbers consist of a large barrel of water with an exhaust piped connected to it.  The pipe extends outside. Pine Cleaner and Liquid Smoke are added to the water to change the smell. The exhaust air is moved through the liquid and the smell is covered.

Chemical Sprays

Chemical sprays are used to mask the smell of pot.  These should only be used outside of the grow room.  The best are the industrial ones.  We do not recommend you use these alone it is best to use them in conjunction with another odor control device.

Ozone Generators

 Ozone generators-generate ozone.  Ozone is an unstable oxygen molecule that can change the molecular structure of particles that come into contact with it. The end result is total odor elimination inside the grow room. The proper way to use it, is to connect its exhaust system into your grow rooms exhaust system.  Ozone can be harmful to plants and people alike, so be careful. Furthermore, ozone generators are quite expensive

Increasing Potency

          Cannabis stores THC in trichomes.  Trichomes and are used by plants for many different reasons. Cannabis uses its trichomes to produce THC, or seeds. Large trichome production is an indication of a potent plant. This is due to the resin that courses within the trichomes. Cannabis converts cannabidiol (CBD), and cannabichromene (CBC) into THC. If you encourage the plant to make this transition its THC content (potency) can increase.

Environment

As discussed before, you must have superior genetics to produce quality marijuana, but genetics is only three fourths of the plants potency potential. The genetic structure only plays a 75% of the role in determining the quality of the bud. The rest is influenced by conditions such as light, temperature, humidity, ultraviolet light and nutrition. 

Humidity affects resin production- low humidity levels during flowering will increase THC potency. However relatively moderate levels during vegetation usually helps the plant produce more potent levels of THC, later, during flowering.  It sets the stage, so to speak.  During flowering, it is best to keep the humidity level low-this compels the plants to produce more resin, in order to protect it from drying out.

Flushing

Pay close attention to the last stage of growth, it can affect potency. Excess nutrients in the plants cause an unfavorable taste.  Flushing is used to clear excess nutrients from the plant. Flush plants with only ph adjusted water during the last week, before harvest. 

Speculation suggests that this makes the plant use up stored nutrients that may affect potency and taste.  It does not have a direct affect. However, the taste increase does create the sensation of higher potency as the stress affect by users

Pruning

During the vegetative stage of growth the plants must be pruned.  Why you ponder?  Well pruning encourages the plants to remain healthy and prevents the plants from becoming too large.  It allows the plant(s) to focus its nutrients and energy to the parts of the plant you want to grow, like the buds for example.  The basic concept of pruning is to remove branches and leaves out of the way.  In other words pruning is just clipping your plants branches.

Lights

The most potent crystallized buds usually are grown under a combination of HPS and MH lights.  This is a direct affect of the amount of UV wavelengths present.  The size of the bulbs is negligible, but what is important is the combination of the two. If you want to increase potency using black lights, go to that blog entry now.

Harvesting

Harvesting right after your dark period will ensure higher THC content.  This is due to the night production of THC.  During the photo period the light can diminish the potency of THC because it has the ability to break the compounds chemical bounds.   You should also wait for about 3/4, or less, of the buds to turn brown, or change color before harvest. This ensures the glands are swollen with the maximum amount of THC.  After harvesting hang buds upside down; this will allow help the THC concentrate in the trichomes.

Pruning

The second function of pruning can be considered more or less trimming.  If plants are left to grow they can reach heights of six feet, or more.  This is undesirable to most gardeners because it consumes too much space, and requires raising the light source every couple of weeks. This is just not practical for most gardeners who prefer to keep their plants short and bushy.  In order to do this, they employ the pruning technique. To keep your plants small in size you need to start prune when the plants show a fourth set of leaves.  To start with, pinch one leaf off that is located in between two other leaves, on the highest point of the plant.  This causes the plant to produce two new growing tips in its place which will grow in a more vertical direction

Supercropping

Supercropping is just another description for bushy growing. There are many different techniques used to grow a plant in this fashion, the most commonly practiced is the tying method.  The two major reasons this technique is used is; one, to encourage horizontal growth; and two, to control the canopy. The first part begins when the plants are a couple of weeks old; the second takes place during flowering.