Previously Asked Questions

We have just recently added this service to the website so there aren’t a lot of tips on file yet, but as time goes by the file will grow.

NOTE: Now you can receive your weekly tips directly in your e-mailbox. The professor will e-mail you his periodic tips FREE. Now you’ll never miss a hot tip!  Click Here To get your tips e-mailed.

NOTE: If you have a tip that you would like to share please feel free to send it to The Professor. He’s always looking for good tips to pass along. Click Here to send tip.

Growing Medium

Coco fiber is the number one growing medium in the world. When using coco the medium does not want to release calcium and magnesium easily to the plants, so nutrients specific to coco have become very popular. If not using a coco nutrient it is important to add a calcium magnesium supplement, such as magical or cal mag.


When ever you spray anything on your plants, whether it is for pest control, fungicide or to foliar feed you plants. You should always use a wetting agent also referred to as a surfactants. The purpose of this is to break the surface tension on the leaf so that product will be absorbed rather than running off.

Nutrient Buildup

Weather gardening in soil or a hydroponic system nutrient buildup is a common problem, it is strongly recommended to flush your medium every two weeks. The best way is to use plain p h adjusted in soil and 1/4 strength nutrient in hydroponic medium use 3 to 4 times the amount of solution you would normally use, water plant at the time you normally would just extra heavy


Composting is the decomposition of biodegradable organic matter, producing compost.

Compost serves as a growing medium, or a porous, absorbent material that holds moisture and soluble minerals, providing the support and nutrients in which most plants will flourish. To maximize plant growth, it is sometimes necessary to dilute compost with soil or peat to reduce salinity.

An effective compost pile is about as damp as a well wrung-out sponge. The necessary material should be added, or the pile should be turned to aerate it and bring the outer layers inside and vice versa. You should add water at this time to help keep the pile damp.

Compost should not contain any animal products, as it can attract local wildlife.

A compost pile takes at least three months from beginning to end before it is usable. So it is usually a good idea to have more than one bin or pile going at once if you are wanting to use the compost on a regular basis.

What’s the best?

We hear this everyday, usually more than once. What’s the best nutrient? What’s the best system? What’s the best light? What’s the best______? You fill in the blank.

We in reality, get a bit weary of having to answer these questions repeatedly. We of course will cheerfully respond to these inquires when asked, as that is our job. The people who ask these questions probably get just as weary listening to the answers because more often than not there isn’t a clear cut “BEST” of anything. It is like asking what kind of car is the best. Or what color is best. It is in most instances a totally subjective answer. People many times just don’t want to hear an indefinite answer. They want it in black and white, a confidant “THIS IS THE BEST”. But in reality all you are getting is a personal opinion (although it may be a very educated opinion, it’s still an opinion).

That being said. I am about to reveal to you a “BEST”. The question that we here the most is probably: “What’s the best hydroponic system?”

OK here it is – My definitive answer is – It depends………OK so I can’t really pin it down to one system that is clearly better than all others. I can however, bring it down to two types of systems that I feel are at least slightly superior to the others.

For those people who subscribe to the KISS (Keep It Simple Stupid) theory, and I am among them, a simple Ebb & Flow (flood & drain) system is hard to beat. Ebb & Flow systems are very simple in design and operation. There is very little to go wrong with an Ebb & Flow set-up. One of the few downsides to an Ebb & Flow system is a trait shared by any “recovery” system (that is a system that recovers and reuses the water & nutrient), When you recover the nutrient solution the nutrient levels as well as the pH can vary. The result is a basic inconsistency. Things may not be the same from watering (feeding) to watering. This is the reason that large reservoirs are recommended. Large reservoirs will buffer the changes.

To prevent the variations found in recovery systems you must use a non-recovery (run to waste) system. You don’t reuse the nutrient solution. You water the plants and whatever runs off is disposed of. I personally use the run off on house plants or my yard. The obvious advantage to a non-recovery system is that nutrient strength and pH are stable and the same every time you water. You lose some nutrient solution as you need about 10% run off to prevent nutrient build up in the root zone.

A non-recovery system can be very simple. A hand watered pot is generally a non-recovery system. You can’t get much simpler than that, only one moving part… However automating a non-recovery system can be a bit tricky. Rather precise timing is required to prevent either an under watering situation or a over watering situation where you would loose a great deal of nutrient solution due to excessive run off.

Most non-recovery systems are based on a “Drip” system as this is the easiest to set up in a non-recovery scenario.

So there you have it, a semi-definitive look at the best hydroponic system(s). Of course this is just one guys opinion, I could be wrong.

For more on the differences between systems  Click Here

How Often Do I Need To Replace My Lamps (Bulbs) In My Grow Lights?

Many gardeners use grow lights either as the only light source or as supplemental lighting. Even many outdoor organic gardeners use artificial lighting for several reasons. Getting a jump on the growing season is one reason. Starting plants indoors before the weatherman allows planting outdoors. Getting cuttings rooted is often best done indoors with artificial light as well.

The problem is many gardeners will use a lamp until it simply will not light up anymore. It still fires and looks bright so everything is good, right?……………Nope, not necessarily.

There is one thing in common with any source of lighting with a usable spectrum of light for gardening. They lose light output slowly over time. Every time the lamp is fired (started) it gets just a tiny bit dimmer. This holds true for High Intensity Discharge lamps (Metal Halides and High Pressure Sodiums) as well as any type of fluorescent lamps.

Now, given the fact that light is horsepower for plants, with a direct relationship between light levels and plant growth,  you can see the obvious outcome. Plant growth and yield slowly diminishes over time in direct relation to the light output of the grow light. If you lose 20% light output you lose 20% plant growth.

So…….How often do you need to replace lamps? It varies due to the amount you use the light. Generally speaking Metal Halides lose about 30% in an average year, High Pressure Sodiums lose about 20% in the same time. Fluorescents dim at about the same rate or faster. So what is an “Average Year”? Basically it is firing the lamp and running for 12-16 hours once a day for a year.

What we recommend is that you replace Metal Halide Lamps every year, High Pressure Sodium and Fluorescent lamps should be replaced every year to a year and a half.

Obviously if you only use your light for a few weeks in the early spring time to get a jump on the season you can go for years without lamp replacement.

Air Flow – Is it Necessary?

This is another question that we here often. The answer is Yes. In fact the answer is H— Yes. This is a very often overlooked aspect of indoor gardening as well as greenhouse gardening.

In nature the air is normally in perpetual motion. This constant motion accomplishes many things from helping to strengthen plant stems to helping with plant reproduction in many species of plants. Air movement (wind) is an important aspect of plant growth.

In the greenhouse / indoor garden you must artificially create wind. This is usually accomplished with the use of oscillating fans. If you are adding supplemental CO2 to the garden an oscillating fan is the best way to disperse the CO2 and to keep it mixed with the air. In a still air environment the CO2 will actually settle to the bottom of the garden where it doesn’t do any good, in fact it can be harmful in the root zone.

Fan driven wind in the indoor garden environment strengthens plants stems by moving them around slightly, it’s kind of like exercising your plants. The breeze also keeps the air fresh around the surface areas of the leaves so there is a constant supply of CO2. Without air movement the air right around the leaves will become stagnant and plant growth will slow. Also a lack of air movement in a moist environment will help with the spread of mold and mildew.

Wind will also cool a plant via transpiration. The same way the wind will cool a sweaty human.

Of course, like most things, wind can be over done. You don’t want near hurricane winds. Just a nice summer breeze.

How Much Light Do I Need for Indoor Gardening?

We here this question on a daily basis. It is a very good question, especially for someone about to lay out big bucks for a lighting system.

The answer isn’t totally cut and dry, but for the most part the best answer is “The more the better.” Particularly for full sun loving plants. Light is to plants what horsepower is to a racecar driver, a very good thing that you can never have enough of.

The amount of light is the single biggest limiter of plant growth in an indoor garden. The amount of light is directly proportional to the amount of growth. In other words, if you double the amount of light you will double the growth of your plants (assuming all other parameters remain constant).

A basic rule of thumb for good healthy growth is: 30 – 35 watts per square foot minimum. In other words a 400 watt H.I.D. light would adequately light an area of between 11.5 and 13.5 square feet (or roughly a 3ft x 4ft area). I know of gardeners that run 125 watts per square foot or more. They report amazing results. Sometimes a smaller garden will outperform a large one.

The biggest mistake made by beginners is to spread the light way too thin. We have had people upset by poor growth only to discover that they are trying to light a huge area with a tiny bulb. There is no free lunch. Sizing a garden to match a light is critical for optimum plant growth.

Can you have too much light? I doubt it. As long as you can control the heat generated by big lights. Artificial lighting is no match for the sun as far as amount of light. Put a 1000 watt Metal Halide or High Pressure Sodium outside at high noon on a bright sunny day and you probably can’t notice that it’s even on.

Heat can be a huge problem in some areas of the world (like here in Florida). So light selection must consider this fact as well. All the light in the world will not help if the temperature of your garden is sky high.

As long as heat is controlled by air-cooling the lamp, water-cooling the lamp, air conditioning or venting the garden then use as big a light as you can afford.


The Importance Of Reservoir Water Temperature

Water temperature is an often overlooked yet extremely important aspect of hydroponic gardening especially in water culture or aeroponic farmers. As summer rapidly approaches I think it is important to discuss this issue.

Water temperature plays an important role with the oxygen content and with bacteria growth in a typical hydroponic reservoir. When water temps rise the oxygen levels drop and bacteria growth increases. Generally speaking water temperature should be in the 68° to 72° F. range. If gardening outdoors you might want to bury the reservoir as much as possible. The ground will help insulate the reservoir. In severe conditions many growers will purchase expensive chiller units that will cool the reservoir to a specific temperature. A much cheaper method is to freeze bottles of water and drop them into the reservoir when needed to control temps.


Foliar Feeding Basics

We often receive questions about foliar feeding plants. So I thought I’d try to shed some light on the subject. I briefly cover the topic, if you are interested in more info visit the link below for a much more detailed article written by Dr. Lynette Morgan.

“What is Foliar feeding?”
Foliar feeding is simply a different method of feeding your plants by spraying the leaves of your plant with a nutrient solution.

“Simple enough, but what are the advantages of this practice?”
The main advantage is speed. Plants can absorb nutrients 9 to 10 times faster through their leaves than they can through their roots. This is especially true for the absorption of micro-nutrients.

“Why is it so much faster than regular fertilization practices?”
Basically, the plant can absorb the complex molecules directly into the leaf of the plant which is where they’re needed. For a plant to absorb through the roots the plant must breakdown the molecules transport them through the roots and up the stem and finally to the leaves. This process works well but it is much slower and requires the plant to expend energy that it could otherwise use for growth.

“So why would one wish to use this method?”
It is the fastest way to “fix” a nutrition deficiency. For example; if you developed a magnesium deficiency (often caused by using “hard water”), you could foliar feed with a solution of water and Epsom salt mixed at a rate of 1/2 to 1 tsp./gallon.

There are many gardeners that use foliar feeding exclusively. Periodically spraying with a nutrient solution and then simply watering with pure water, keeping the root zone free of nutrients. Using this method it is relatively easy to keep the nutrient levels as high as possible without burning the roots.

“Do you need special fertilizers for foliar feeding?”
There are a few fertilizers/additives that are designed specifically for foliar feeding but basically any nutrient can be used. Some of the products specifically designed for foliar feeding include: Bill’s Perfect Fertilizer, Spray and grow, Botanicare Profiler and Dutch Master’s Folitech, Max-FX and Penetrator.

To use a conventional nutrient (designed for fertilizing the roots) as a foliar fertilizer you would mix it at 1/4 strength of the normal mixing ratio. NOTE: If you mix it at the normal strength and apply by foliar feeding you will probably kill your plants due to over fertilization.

“What else can foliar feeding do for me?
Foliar feeding is also a good way to help a plant recover from a severe “over fertilization” problem. Misting the plant with plain water will quickly dilute the excess nutrient. A stressed plant can often be saved and/or revived by foliar feeding with a mixture of water and Superthrive. Superthrive is a vitamin and hormone supplement that is (in my humble opinion) a miracle worker. Nothing is better for reviving damaged plants and it is a good supplement to use on a regular basis. It’s like giving your plants a vitamin pill everyday.

For a great article on Foliar Feeding Click Here

To view foliar nutrients and additives in our catalog CLICK HERE.

Preventing Salt Build-up In Growing Media

Salt build up can cause major consequences to your plants, none of them are good. Very healthy and fast growing plants can brown up and die in a very short time as a result of severe salt build up.

To prevent salt build up it is best to flush your system/growing medium every two weeks. Use either a commercially available leaching agent like Clearex or Final Flush or you can use a 1/4 strength nutrient solution. Plain pH adjusted water can be used as well if you already have a salt build up. Always pH adjust whatever flushing solution you use.


Checking Soil pH

To accurately test the pH of soil, fill a shot glass (or other small glass container) 1/2 way with the soil to be tested. Add distilled water and mix well. Allow the mixture to set for a while to allow the “dirt” to settle giving you a “clean” sample to check. Pour off the clear water and then test the water for ph.

For more info about pH CLICK HERE

To view pH testers in our catalog CLICK HERE

Organic Treatment for Blossom End Rot

Spraying (misting) your plants with milk is reportedly a good totally organic cure for blossom end rot. Apparently its the calcium in the milk that does the trick. If you are growing in soil you can pour the milk directly on the ground around the plants instead of spraying the plants.

A Good Organic Fungicide

If you need a good safe organic fungicide simply mix 2 tablespoons of Baking Soda per gallon of water, spay the plants liberally. This puts an alkaline coating on the plants which doesn’t allow the fungus to grow and is completely safe for both plants and animals.

Organic Pest Control

There is an effective, safe, completely organic pest control that is easy to make and use. Simply mix 2 tablespoons of dish soap and 2 tablespoons of vegetable oil per gallon of water. Spray the plants liberally with mixture. This solution works by blocking the insects ability to breath, smothering it. The mixture is a contact killer, which means that you have to spray it directly on the pests in order to kill them. So you may have to make repeated applications.

Purge Nitrogen Before Cloning

To help insure a better success rate with your cuttings it is a good idea to “purge” the nitrogen out of your mother plants before taking the cuttings (clones). Simply drain your reservoir and water the mothers with pH adjusted water only (no nutrient) for a few days, this forces the plant to feed off the excess nitrogen that the plant stores within itself. The end result is that the cuttings will root quicker, and start growing faster.

Emergency pH Adjusters

When you need to adjust the pH of your nutrient solution and you’re out of adjuster you can use white vinegar to adjust your solution down, and baking soda to adjust it up. NOTE: Using these to control pH is fine on a temporary basis, however, they are not very stable and could cause problems if used on a full time basis.

Ideal Temperatures For Cuttings

The success rate for cuttings can be greatly effected by the temperature of the plant and the temperature of the root zone. For most plants the air temperature around the plant should be between 70 – 75 deg. F. The root zone needs to be a bit warmer, with a temperature between 78 – 80 deg. F. Propagation mats are available that will raise the root zone temperature to the proper levels.

Add Dish Soap To Foliar Sprays

When you are mixing a spray for your plants, weather it’s for pest control or foliar feeding, add a teaspoon per gallon of ordinary dish soap to the spray. This will break the surface tension of the water and allows the spray to cover the plants completely instead of “beading up”.

Free Greenhouse Plans

This weeks tip was sent in by one of our customers (Thank you Eric). The following link takes you to a site with free plans for a great little greenhouse that you can build yourself out of easy to find inexpensive materials. CLICK HERE for greenhouse plans.

Organic Compost Activator

Beer makes an excellent organic compost activator, pour a couple of cans on the compost pile every couple of months. The yeast in the beer is the active ingredient.

(Important Update Below)

In a past tip I stated that a great compost activator was to pour beer on the compost. To answer the question that was raised by a some of you…..Yes it will still work if you pass it though your kidneys first. But don’t blame me if you get arrested for indecent exposure, I will deny any knowledge of why you are peeing on your compost pile. :o)

Aeration, Aeration, Aeration

Using organic nutrients in hydroponic systems is becoming very popular. The addition of organic fertilizer is reported to drastically increase both the flavor and/or aroma of the plants. When using organics it is very important that you provide good aeration of the nutrient solution. Aeration is important in any nutrient solution, but lack of it in an organic solution can mean a stinky, stagnant mess. Remember- there is no such thing as too much aeration.

Organic Rooting Hormone

You can use Maxicrop Liquid Seaweed as a 100% organic rooting hormone. This method isn’t as fast as the regular rooting hormones, you have to soak the cuttings for 1 to 24 hours in full strength Liquid Seaweed (Regular rooting hormones need only be dipped for a few seconds).

Lighting Tips

The light energy produced by grow lights diminishes very rapidly, I have measured about a 50% reduction in light energy per foot of distance. Fluorescent bulbs are the worst as they lose almost all their energy within a few inches.

As a result of this loss of energy it is important to keep your grow light as close as possible to your plants, 1 to 2 inches for fluorescent bulbs and High Intensity Discharge (H.I.D.) lamps need to be as close to the plants as possible without burning them. This height will vary depending on the size of the HID light. For more detailed information about lighting for your garden CLICK HERE.

Organic “Tea Bag”

An easy way to add many types of organic fertilizers to you hydroponic reservoir is to make a “tea bag” out of an old pair of panty hose. Put the fertilizer into the panty hose and tie it shut. Hang the tea bag in the reservoir and suspend it directly over the air stone. Aeration of the reservoir is very important, especially when you are using organic nutrients.

Organic Treatment For Blossom End Rot

Spraying (misting) your plants with milk is reportedly a good totally organic cure for blossom end rot. Apparently its the calcium in the milk that does the trick. If you are growing in soil you can pour the milk directly on the ground around the plants instead of spraying the plants.

Being Careful

What hobby could be safer than gardening? Especially if that garden is indoors? You may be hard pressed to think of a hobby with less risk of personal injury. However there is a risk that might not seem too plausible. That risk is fire. It doesn’t happen often but it can happen.

We have seen only one fully involved fire, where the fire department was required and the dwelling was pretty much destroyed. However we have seen literally dozens of “close-calls” where fire didn’t actually start but there was lots of electrical arcing, smoke and noxious fumes. We have heard a few reports of a fire breaking out but was discovered quickly and extinguished before any major damage was done. Scary stuff indeed.

The cause of all these incidents was basically the same. Poor electrical connections where high draw electrical devices plug in (mainly grow lights and “window-shaker” air conditioning units).

What seems to happen in most cases is that the plug isn’t plugged all the way into the receptacle. This lets moist air get to and start to corrode the contacts of the plug. Eventually the corrosion can lead to an arc when the device turns on and there is a sudden draw of electricity. This arc causes even more corrosion as well as lots of heat. In some instances the arcing can cause enough heat to start melting the plastic plug and/or socket. Once the plastic starts to melt there starts a kind of chain reaction where the melting plastic creates more arcing, building intense heat which melts more plastic…..etc. if you are lucky the circuit breaker will trip and there will be no further problem. Once in a while the arcing will not draw enough current to trip the breaker and things can get intense sometimes causing a fire.

In grow rooms the air is frequently very humid and can speed the corrosion of the plugs/receptacles. I have seen cases where light ballasts are positioned in a garden where nutrient solution actually splashes onto the ballasts and their plugs. This is doubly problematic as nutrient solutions are salty which speeds up the corrosion process. The pictures below are from our “Hall of Flame”. They show what can happen when plugs are left partially out of the sockets.

Fact is that virtually any electrical connection can corrode and arc. This is particularly true with equipment that draws heavy current loads. It is also fact that plugs have a way of working their way partially out of their sockets. Vigilance must be maintained and you should frequently inspect your connections, making sure that they are snug and corrosion free. Things to look for are very dirty or discolored connections. I have also noticed that frequently the plastic of the plug begins to swell and get slightly melted looking around the metal contacts.  If you see anything that doesn’t look right – get it fixed – now!! Be Safe!!!

Mixing Nutrients

Do not mix all of your nutrients, additives, or any other product as a concentrate to try to cut corners. Add each separately to the reservoir. Some products as a concentrate do not mix well together and will actually cause each other to go bad.

Adjusting pH

When testing the pH in your reservoir or watering container, always wait until your nutrients and additives have been added before adjusting the pH level. By trying to adjust it before adding them will result in wasting the pH adjusters. Nutrients and additives will change the pH levels.

Click here to view our line of pH adjusters.

Gardening In The Summer

Looking for more ways to garden outside during the heat of summer?
Try using shade cloth over your garden. Not only does it help protect your plants, but it makes it nicer on you when you are working in the garden. You can get shade cloth at most home improvement stores.
Another good suggestion is to let your hose run a few minutes before watering your plants. That way the plants get a drink of fresh cold water instead of the warm water in the hose.

Water Preservation

Looking to water less? Come see us at Simply for products to help save on watering.
  Soil Moist is an organic “agro-polymer” that absorbs water much like a sponge. Used as directed, it can double the amount of water retained by the soil. Totally biodegradable and non-toxic. Can also be added to sod and lawn to reduce watering needs.
  Hydretain is a blend hygroscopic and humectant compounds that attract and hold moisture, like tiny “water magnets” within soil. Hydretain manages available moisture within the soil, extending watering intervals of indoor and outdoor plants, flowers, vegetables, shrubs, trees and grass by as much as 2 to 3 times. Each application reduces watering for up to 3 months.
  Vermiculite is a sponge-like medium that helps hold and retain moisture allowing for less watering. It can be mixed with any other growing medium.

Click here to view Soil Moist.

Growing In Coconut

Coconut fiber is rapidly becoming one of the most popular growing mediums in the world. In fact it may soon be THE most popular. It is the first totally “organic” growing medium that offers top performance in hydroponic systems. Coconut fiber is essentially a waste product of the coconut industry, it is the powdered husks of the coconut itself.

There are many advantages – it maintains a larger oxygen capacity than rockwool, yet also has superior water holding ability than rockwool which is a real advantage for hydroponic systems that have intermittent watering cycles.

Coconut fiber is also high in root stimulating hormones and offers some protection against root diseases including fungus infestation. Dutch growers have found that a mixture of 50% coconut fiber and 50% expanded clay pellets is the perfect growing medium.

One word of caution about coconut fiber, you must be careful when you purchase coconut fiber. There is a commonly available, lower grade of coconut fiber that is high in sea-salt and is very fine grained. This lower grade coconut fiber will lead to disappointing results when used in a hydroponic system.

Click here to see our NEW Canna Coco.