ASK The Experts
Discussing
Digital
Ballasts
I use a digital ballast. What
is the purpose of the
dimmable feature? What
setting should be used
during the veg stage, and what
setting should be used during the flower stage?
-Lee-Roy
Thanks for writing in, Lee-Roy. You are not the only grower to
question the dimmer function of your ballast. I also use digital
ballasts, and I was hesitant to run my lamps at any setting other
than 100%. After all, the bulb wasn’t designed to function at
anything other than full power.
These days, I am a big fan of dimming in certain situations. The
most common use of dimmers is for the occasional heat wave.
When outside temperatures become unseasonably warm, it gets
harder to cool those hot lights indoors. Turn them down to 75%
or 60% to achieve ideal indoor temperatures (75 to 82°F). Once
outside temps have gone back to normal, crank the lights back
up to 100%. A slight reduction in light for a day or two is better
than overheating your garden.
Low ceilings and young plants are also reasons to dim your
lights. Some growers will keep their lights 3- to 4-ft. above young
seedlings and rooted cuttings for the first few days. If you have
low ceilings, it might be impossible to raise the grow lights that
high. Dimming the lights for the first few days is a great alternative to raising them.
Regarding vegetative vs. flowering, the dimming option is irrelevant. Unless you are dealing with fresh new plants, or one of the
aforementioned scenarios, keep your lights running at 100%. I recommend T5 fluorescents for vegetative growth and high-pressure
sodium for flowering. With two lights, you will always have vegetative plants and flowering plants for steady harvests all year long.
Peace,
Casey Jones Fraser
Calculating Calcium
“The Calcium Highway” article in
Maximum Yield January 2014 brings
to light the need of high calcium inputs
in certain situations. My question is,
how can I get my calcium high enough
without affecting anything else?
-CH
Calcium must be present in the root zone
in a solution for availability up to 200 ppm.
Soil-based growers have fewer issues as soil
calcium sources are usually sufficient at providing proper nutrition. Irrigating with water
that is slightly acidic (pH 5.5) maintains
maximum availability of calcium to plant
roots. However, hydroponic growers that use
predominantly clean water may have lowered
calcium levels that cause deficiency symptoms. In hydroponic systems, calcium levels
are generally sustained with calcium nitrate
or other calcium type salts. However, in
specific low-use cases, it may be cost-effective
to supplement with fine grain or nano-sized
calcium carbonate products. They can be
mixed with fulvic acid or humic acids to help
with solubility.
Hope this helps,
Russell Landry
Russell Landry is the former vice-president
Casey Jones Fraser owns Garden Grove Organics, in
Northern Kentucky/Greater Cincinnati. He has a degree
in communications and electronic media. He believes that
indoor gardeners can achieve the highest qual ity crops
and maximum yields when proper science is applied.
Since 1998, Casey has been testing various nutrients and
supplements in search of outstanding harvests.
20
Maximum Yield USA | March 2014
of the Great Pumpkin Commonwealth
and its competitive weigh-off sites held
worldwide. He is now the current president
of the Giant Vegetable Growers of Ontario
(gvgo.ca). Russ grows giant pumpkins,
tomatoes and squash. He has written
numerous articles featuring methods to
increase vegetable size and fruit yield.