Ask Jack
Dear Jack,
I purchased 20 young discus from a
local tropical fish breeder, at the same time
selling 10 of them to a local friend. All 20
fish are from the same pair of breeders.
Both my friend and I have had about the
same amount of experience with freshwater
tropicals, and living in the same city, we’ve
found that we both have been able to use
our local municipal water for all our fish.
At this point though, things change a
little. He feeds the discus three times daily;
I feed mine twice daily. He makes two
to three weekly water changes, each of
approximately 40 percent, while I make
one 30- to 35-percent water change weekly.
His discus are fed frozen adult Artemia and
frozen mosquito larvae, while my discus are
fed my original discus formula, consisting
of liver, heart, green vegetable, seafood, and
flake and pellet foods.
Why are his 10 discus approximately 25
percent larger than mine?
Joseph Levine
Syracuse, New York
Another thought that just came to mind is
that without all the information necessary
from you, is it possible that neither your fish
nor your friend’s fish are of the correct size?
You have one advantage over your friend in
that your fish are being fed correctly, and he
has presently one advantage over you, in that
his discus are receiving a much better program
of water changing [see sidebar on p. 36].
How about filtration? If neither of you has
well-functioning aquarium filtration for your
discus, an ammonia reading of as slight as
0.5 mg/l will not allow the discus to grow
properly. Lesser amounts of ammonia, as well
as nitrites, can be tolerated for short periods,
but essentially your discus should have neither
in their tanks at any time.
Do both of you have test kits to determine
whether or not your discus are in good-quality
water? I’ve said many times that I never could
understand how so many discus hobbyists
attempting to successfully breed their fish didn’t
have an inexpensive microscope. But even more
amazing is that I’ve come in contact with discus
enthusiasts who don’t maintain even the basic
inexpensive test kits to measure the readings for
water pH, ammonia, and nitrites.
Jack
WATTLEY
Jack Wattley is worldwide
the most recognized name in
discus breeding. Breeder, judge,
collector, scholar, Jack is the
foundation on which modern
discus keeping has been built.
He has been sharing his
experience and knowledge—
and the discus he breeds—with
aquarists throughout the world
for decades, and just one of
his many awards was his
recent Lifetime Achievement
award from the ACA. Long
past the age at which most
people retire, he still serves
as ambassador of discus and
goodwill across the planet.
Dear Joseph,
I see that several important points were
not explained to me. Nothing at all was said
regarding the sizes of the two tanks. That
certainly has to be part of the equation. Without
my knowing the size of your aquarium I can
see your 10 fish in a 10-gallon setup, while
your friend’s discus are enjoying 40 or 50
gallons of fresher water, with much less chance
of any ammonia or nitrite buildup.
Nothing was said regarding the amount
of food being given to your fish, nor to your
friend’s fish. The diet your discus are given is
superior to that of your friend’s fish, but is it
at all possible that his discus are receiving a
very adequate amount of food, while your fish
with their superior food are not receiving a
sufficient amount in order to grow properly?
Dear Jack,
I have two very important questions to ask
you. Would you recommend using a diatom
filter on a discus tank? And aside from
Echinodorus, which other aquatic plants are
compatible with discus? Thanks.
Benito Nava
Mexico City
Dear Benito,
I haven’t used diatom filtration in our discus
hatchery for years. I know it’s being used, and has
been for some time, but I’ve never really found it
necessary. However, if you want to clear up a
temporary clouding condition in the aquarium,
diatom filtration can be very effective.
