November 7th, 2008 · No Comments

Hey Erik,

The questions you’ve been answering lately are really interesting subjects I haven’t even thought of before. You’re “blog” is a wealth of knowledge and
one of the greatest resources I’ve found on the net. Keep up the good work!
I’ve got some questions I hope you can help me with. Feel free to answer all, one, some, or none of my questions. Hope to hear from you soon!

TJ

1. I was wondering if light can be absorbed by the bottom of the leaf? i.e. reflective surface, or an extra light surface pointed up from below the plant.

Great question! It would seem that the plant collects the majority of the light energy from the upper surface of the leaf. This can be said of most plants, while there are a few plant types out there where there is no real distinctive upper or lower leaf. The underside of the leaf is usually where most of the “breathing” occurs.

However, plants that receive either reflected or direct light from lower down or underneath the canopy tend to have tighter and more efficient growth patterns with a higher degree of branching. Lower branches and leaves that receive increased light levels will yield more and produce higher quality flowers and fruits.

2. You’ve recommended keeping nutrient water cool for aeroponic growing.
But for growing in soil and soilless with both chemical and organic fertilizers, will keeping nutrient solution between 68 and 75 degrees with a frozen water bottle replaced regularly in my resevoir help oxygenate the water, along with an air pump; or will keeping the water cold and air pump continously running, not be advantageous to beneficial micro-organisms?
Or will the water temp being cool; not affect the oxygenation of water, number of micro-organisms, and absorption through the roots enough to make a big enough difference to worry about it?
Or am I just all turned around on the subject, and water being room temperature is the most beneficial for my plants?

There is a drastic relationship between the temperature of water, and it’s ability to hold Dissolved Oxygen (DO). Cooler water temperatures means more DO. Even when aerating the water, it can only hold “X” amount of DO, as determined by the temperature and other factors.

The metabolic rate of the plants root system and micro-biology surrounding it will function at a higher rate with slightly warmer temperatures, so the grower must create a balance between DO levels and the metabolism of the plants and beneficials. Typically, maintaining res temps 65-72 deg F is a healthy balance. Serious problems can arise of res temps run too cold or too warm. Growing mediums will help to buffer the roots somewhat, and provide a good mechanical substrate for the beneficials you introduce into your reservoir.

3. I know you’ve answered this before, but I’m having trouble finding the answer. What is the AN supplement that is an excellent chelator for nutrient absorption
during heavy feedings?

H-2 and F-1 are the ones for the job in this departments, especially if you grow organic.