Raising Discus Our Way - Coastal Aquarium Society

One of the most rewarding sights in the aquarium hobby is seeing a proud pair of
Discus carefully fan the nest and chase off “intruders.” Eventually they will escort the
cloud of fry around the tank, as they herd them, protect them and teach them to fend
for themselves.
One of the most frustrating
experiences is this hobby is to see a
beautiful pair of fish eat spawn after
spawn of eggs! If you are one of the
lucky aquarists who has a pair that
raise their own fry, sit back, relax, and
enjoy one of the most rewarding
experiences in the hobby. The only
thing you need to worry about is what
to feed the fry after they become freeswimming. We’ll cover this later.
• Jack Wattley’s 3-Part TFH Article
• Internet Information
• General Disclaimer
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Temperature 82-86 Degrees
Hardness – 180-190 (TDS)
pH – 7.2 – 7.6
Water Changes – 50% Weekly
Filtration – Sponge Filters & Rocket Filters
Regular Tap Water - No R/O water or
Buffers!!
Sexing discus has always been problematic at best.
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There is so much information available on-line.
It seems that there are as many ways to sex discus as there are
discus breeders!
In our experience, the only sure-fire way to accurately sex discus
is when they actually form a pair and lay fertile eggs!
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A recent article in a European
publication called “Diskus Brief”
described a method for sexing Discus
that has proven to be very easy and
highly reliable for us. The method uses
"geometry" to determine sex.
Your Discus must be mature fish for this
to work. Otherwise they will all appear
to be females.
Picture a discus facing to your left ... you
would be looking at it's side. Find the
Dorsal and Anal fins and look where the
fins slope down toward the tail.
The Dorsal and Anal Fins become
(almost) straight after the fins curve
down (or up) toward the tail.
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Extend an imaginary line along this
straight section of the 2 fins back toward
the tail which just touches the Dorsal &
Anal Fins past the tail.
These two imaginary lines should
intersect behind the fish. The key to
sexing the fish is where the lines cross
the Caudal fin.
If they pass through the Caudal Fin, the
fish is most likely a FEMALE.
If they miss or just touch the Caudal Fin,
then most likely it is a MALE.
Discus can be housed and spawned in any number of
aquariums, but here are some considerations:
• 6-8 adult fish in a 55 gallon aquarium
• Blind Date
• 20 – 30 gallon “high” tanks seem to
work best for individual pairs.
• Bare-bottom tank
• Blue LED “night light”
• All lights are on timers
• Sponge Filter
• Diet
• Slate (easily removed)
Now that you have had a pair of
Discus successfully spawn, and
the eggs are in your tank, the
next questions is “Now what?” If
you have ever hatched/raised
angelfish before, you’re light
years ahead as the process is
very similar.
Long before your fish ever
spawn, you should decide on
the process you’re going to use
to hatch them. We would
recommend using a dedicated
hatchery tank and an individual
hatching jar for each spawn.
While it may sound complicated
at first, the process is very
simple, and the pictures should
clarify the process significantly.
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The hatchery tank is simply a 10 gallon tank that is filled halfway
with water.
The hatching containers with the eggs will be set inside the tank.
A submersible heater adjusted to 82-84 degrees is attached
horizontally to the back of the tank, along the bottom. This will
maintain the proper temperature for hatching.
A glass cover should be used to maintain the temperature and
control evaporation.
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An airline attached to a 12” piece of rigid airline tubing, and an air
stone provide the necessary water circulation.
A sponge filter completes the setup. Using a 10 gallon tank as the
“hatchery” allows you to add as many as 5 of the 1 gallon
hatching containers (5 separate spawns) to the same tank without
worrying about temperature. While we use a 10 gallon tank, you
could just as easily use another size tank that you happen to have
handy.
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For hatching containers, we use 1 gallon, clear plastic containers
that we picked up at Wal-Mart for about $2 each. These
containers are actually canisters, for storing sugar, flour, etc.
Generally, we allow the eggs to remain with the parents for a couple
of hours after it appears that the spawning process is over. This
helps ensure that enough time has passed to ensure that the eggs
have been fertilized by the male. There’s nothing worse than pulling
out a large spawn from your special pair only to find that you
removed them too early and they are completely infertile.
Once spawning has been completed:
• Siphon water out of the spawning tank and into the plastic
container, just up to the top line of the container. Don’t fill it too
high or when you put your hand in the jar, water will spill all over
the floor (and you).
• Remove the spawning slate from the tank. Don’t worry about
knocking the eggs off the object as they are very sticky at this
point, and are actually pretty hard remove.
• Place the slate into your container of water. Again, don’t worry
about them being exposed to the air. They are out of the water
for such a small amount of time that it will not affect the eggs in
any way.
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Carefully lower the slate bearing the eggs to the bottom of the container.
Try to stand the slate upright, leaning against the back of the jar, with the
eggs facing the center of the jar.
We then add 8 drops or Methylene Blue to the water. This will turn the
water (and most everything in the container) a dark blue. No matter how
experienced the parents, there will always be a certain number of eggs
that are infertile. This can range from just a few, to as many as 50%.
Roughly 24 hours after they are laid, any infertile eggs will become an
opaque white. If left in regular water, these infertile eggs will become
covered with a fuzzy fungus. If left untreated, this fungus will quickly
spread to the good eggs, or newly hatched “wigglers” and kill them.
Methylene Blue is an anti-fungal and when added to the water will
prevent the “bad eggs” from getting coated with fungus and spreading to
the good eggs. It will not have any adverse impact on the good eggs.
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The entire hatching container is then lowered into the hatchery
tank. The heater in the hatchery tank will maintain the proper
temperature in all the hatching containers. It’s important to make
sure the water level in the hatchery tank is approximately the
same as the water level in the hatching container. A little less
water is OK, but makes it harder for the heater to maintain a
steady temperature. Too much water in the tank may cause the
container with the eggs to float up and tip over….definitely not a
good thing. Remember, as you add more containers, you will
need to remove some of the water in the hatching tank or they
will start to float!
The last step in the process is to add an air stone to the container
and put it as close to the bottom as possible. The flow of air should
be strong enough to provide good circulation in the container, but
not strong enough to dislodge the eggs. I would describe it as a
“medium” flow. You can now sit back and take a break. Your job is
done (for at least a couple of days). You should check on them
periodically. After about 24 hours, the bad eggs will turn white. The
fertile eggs will be a darker color, and if you use a flashlight (really
the only way to see them through the blue) you will be able to see a
dark spot inside the egg. Now you will be really glad you added the
Methylene Blue!
Discus always seem to spawn in the late afternoon or just before
dark. At 84 degrees, discus eggs will generally hatch in about 60
hours (2 ½ days), but should be fully hatched after 3 ½ days. As
they hatch, they may begin to fall of the spawning surface to the
bottom of the container. That’s fine, don’t worry. If raised by their
parents, the parents would gently pick them up and spit them back
on the slate. Don’t try this at home! Trust me, the water tastes
terrible!
At this point, it’s time to transfer your wigglers to the nursery tank.
• This is the heart of our
discus rearing process.
• Made of ½” PVC
plumbing parts (cheap).
• Can be adapted to any
size tank.
• While the rearing
container is small, you
have the benefit of a
large tank.
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Uses a Powerhead,
sponge filter and the
PVC to deliver a steady
supply of filtered water
to the fry.
….And a sponge
filter and heater
completes the setup!
The other two items you will need to purchase are:
Nylon Coffee
Filter – ($6 at
ACE Hardware)
8 ½ x 11”
Food-Grade
Container (tray)
($11 at The
Container Store)
• 5 – 3/8” holes need to
be drilled in the tray –
2“ from the bottom
• You can comfortably
fit 2 coffee filters in
each tray.
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The trays are placed onto the frame of the tank, and airline tubing is
plugged onto the plastic valves and cut to the appropriate length.
The completed
nursery tank in
operation
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Remove the spawning slate
from the hatching jar and
check carefully to make sure
there are no “Klingons.”
Remove the hatching jar
from the hatchery tank.
Place the empty coffee filter
in a 1-quart “Gladware”
container.
Pour some of the water from
the hatching jar into the
coffee filter.
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Using a glass turkey baster,
carefully suck the wigglers off
the bottom of the hatching jar
and squirt them into the coffee
filter.
Since the water will still be a
dark blue, it helps to set the
hatching jar on a white towel to
increase visibility of the
wigglers.
Place the Gladware container
into the water-filled tray on the
frame of the tank, and allow the
temperature to equalize.
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When the temperature has
equalized, lift the filter out of
the Gladware container and
set it into the tray.
Open the air/water valve and
start the water flowing.
The water should be flowing at
a rate just faster than a drip,
(to break the surface tension)
but not a stream.
The fry will bunch together and
form “clumps.” This is normal.
Using a plastic pipette, remove
any dead fry and un-hatched
eggs.
Assuming that the water in the hatchery is at 84 degrees,
somewhere around day 2 (after hatching) you’ll notice that the yolk
sacks are noticeably smaller, and the fry are “scooting” around the
bottom of the filter. Some of them may even be strong enough to
make short “sprints” off the bottom, and up into the water column.
Sometime within the next 24 hours, you’ll look in the filter and will be
surprised to see a whole cloud of fry swimming about in the filter. A
few of them may still be scooting around the bottom of the filterr, but
now it’s time to make sure you’re ready to feed the inevitable swarm
of fish!
The first food for the fry, we use a mixture of powdered egg yolk and
powdered Spirulina.
Powdered egg yolk can be purchased on-line, or
from baking specialty stores (Williams &
Sonoma). It costs about $11 for a one pound
bag. The advantages to using powdered egg yolk
are:
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Finely ground – Perfect size for fry
Pasteurized – No bacteria
Will not spoil – No refrigeration needed
No boiling/peeling eggs
Extremely cost effective
Preparing the Food
In a separate Container – Pill Bottle:
• Mix a teaspoon full of the
powdered egg yolk with a very
small amount of the Spirulina
powder. Just enough to give it a
greenish tinge.
• Put a few drops of water on a
spoon and add a little of the
mixture to the water with a
toothpick.
• When mixed, it should have a
thick, moist appearance, like
toothpaste
Preparing the Food
Using small pieces of dark colored
slate (1” x 1” or 1” x 2”) smear some
of the paste on the lower half of the
slate.
• Smear it as thinly as possible.
• If too thick, it will flake off when
placed in the water.
• Allow to dry for several hours.
• Store extras in refrigerator.
• Don’t be in a hurry to feed them.
Wait at least 12 hours after you
notice them free-swimming to feed
them.
Stand one of the slates upright in the coffee filter with the fry. The fry
will/should immediately swarm the slate, and begin picking off the egg yolk.
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Leave the slates in for 2-3 hours.
Remove slowly.
We feed three separate times (0700, 1500, &
2000).
Feed only the egg yolk mixture for the first 24
hours.
Use a plastic pipette ($5 per 100 on Amazon) to
remove uneaten food after each feeding.
Remember to change the coffee filters every other
day, or as needed
After Day 1, begin adding in a secondary food such
as micro-worms, vinegar eels or brine shrimp.
ü San Francisco Bay vs. Great Salt Lakes Brine Shrimp
ü Size
ü Cost
By day 3, all of the fry should be large enough to eat baby brine
shrimp, and you can discontinue the egg yolk mixture. Use the
“belly barometer.”
To ensure that the fry get off to a great start, we keep them in
the coffee filters for 10 days. We use 2 ½ gallon tanks for the
next stage of the grow-out process.
Through much trial and error, we have found that the next few
steps are critical to the survival of the fry.
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Clean and prep the 2 ½ gallon tank.
Use a seasoned sponge filter.
Heater set to 84 degrees.
Very sensitive to being moved.
Fill the 2 ½ gallon tanks with water from the Nursery Tank.
Lift the filter out of the tray, and set it in the newly prepared
2 ½ gallon tank.
Ø Tilt the filter, and let the little guys out.
10 Day Old Fry in their New Home
Wigglers – Day 3
Wigglers – Day 1
Fry – Day 6
Fry – Day 4
Fry – Day 9
Fry – Day 8