- On wild reefs, over 99% of newly settled Acropora
die within the first year.
- In our aquariums,
even the tiniest of frags of Acropora fair much better.
We don't let algae surround 'em and suffocate 'em.
We protect them from fish
that would wanna eat them and disease,
but we could probably do better than just the minimum.
Hi, guys and girls, I'm Reefman.
This time, it's all about feeding our stony corals.
So I think that most of us feed our large polyp corals,
but it's also important to think about the nutritional needs
of our Acropora and other stony corals as well.
So take a moment to click the subscribe button.
There'll be more videos in the future
on Acropora foods, so watch for those.
And so, with that said, let's dive in
and see why exactly it's worthwhile
to take your time to feed our stony corals.
So it's true that most of the nutritional requirements
that our Acropora have can be met
by their symbiotic zooxanthellae,
but many species can also get nutrition
by just catching things directly out of the water.
Direct feeding like this provides vital nutrients
that they won't be able to get purely
from their zooxanthellae photosynthesizing.
These are things like nitrogen, phosphorous,
some amino acids and trace vitamins and minerals.
Beyond just sort of you know making common sense,
it's actually been proven in research
that feeding corals results in better tissue growth,
a higher rate of calcification, so it's growing faster,
and better overall health and nutrient storage.
In other words, the coral is better,
healthier, grows faster, looks better.
Sounds great, right?
In laboratory conditions, teams feed corals things like
Artemia nauplii, which is a brine shrimp,
and rotifers, but these aren't really available
to the average hobbyist,
unless you wanna culture them yourself.
They're not that hard to do.
If your interested, you can certainly hatch brine shrimp
or even maybe buy the decapsulated eggs
and use those as a feed.
I generally don't wanna mess around with live foods
and having to culture it and refrigerate it.
And that's why I use packaged foods, like Reef Roids
or New Life Spectrum's micro feed for coral.
Of course, when we use those,
we don't know exactly what goes into those foods,
and so, the overall nutritional profile
might not be the best and, well, we wouldn't know.
Reef Roids simply lists marine plankton,
and while we do get a little more information
from New Life Spectrum, it's hard to know
exactly if that's meeting all of the needs of our coral.
So there's been a bunch of research recently
in this area as a way to better grow corals
and then, use those corals to repopulate bleached reefs.
One paper in particular that I would recommend is this one.
It's titled The Influence of Different Feeding Regimes
on the Survival, Growth and Bio Chemical Composition
of Acropora Coral Recruits.
And there's a link in the description
down below if you'd like to check it out in more detail.
They go into more detail than I will here.
So in the paper, the authors are looking at feeding
four different species of Acropora four different diets.
They're using enriched rotifers,
a custom diet that they make themselves,
natural sea water, and then, very finely filtered sea water.
And so, I think their results are particularly interesting
because the species that they're studying
are a species that we commonly keep in our tanks as well.
Now prepare yourself for some butchered Latin,
but these are things like Acropora hyacinthus,
Acropora loripes, Acropora millepora, and Acropora tenuis,
and I know I have several of those in my tank behind me.
So the team enriched their rotifers with Selco S.parkle,
which is a powder you mix up with water
and then, feed to the rotifers to make them more nutritious.
They don't provide the details of exactly
what went into their custom made diet,
but anyway, they feed their corals twice a day,
at 10:00 a.m. and then, again at 4:00 p.m.
Now, they give the corals 20 minutes to feed
without any pumps or water movement.
Then they turn on the pumps just to mix everything up again
and then, give 'em another 20 minutes
to finish feeding without the pumps on.
And then, they calculated the dosage
to be 2.4 rotifers per milliliter of water,
which matches a natural food density
found on reefs around the world.
So those of you who do feed your corals,
do you do it this often, I mean, twice a day?
I don't.
Although I try to feed them most days,
sometimes, it's only a couple times a week.
So they ran their experiment for 93 days
and then, they looked at the growth
and the chemical content of each coral in the study
to find out, did it have any affect?
So it does have an affect, a very strong affect.
Acropora growth as actually best in the tanks
just using natural sea water.
That's great news for those of you near the coast
who can actually get natural sea water,
but for the rest of us, nah.
So growth was lowest in the unfed,
highly filtered sea water tanks,
and these things are basically what you
and I would have if we didn't feed our corals at all.
Depending on the species then,
the enhanced rotifers, or their custom diet,
were the second and third scoring food types
for the overall coral growth and health,
but both diets show an improvement over not feeding at all.
So the key takeaway here that you've gotta remember
is that we need to be feeding our stony corals
just like our fish.
You wouldn't just keep a fish in a tank and not feed it.
Don't do that to your coral.
Turn off your pumps or at least your return pump
and skimmer, and then, give your corals 30 minutes
to an hour to eat whatever you're gonna put in the tank
before turning all that stuff back on.
And I promise you your corals will thank you
with increased growth and better color.
So I hope you found the video and paper interesting.
Please do check it out.
It's really cool.
They have a lot of information in it.
And I hope that they do publish
what their custom feed is sometime in the future
'cause it'd be really cool to be able
to make our own coral food like we can
for a fish video above.
The study was specifically about larval coral
because they're trying to reproduce it
and then, repopulate reefs, but I do think
that it's applicable, just in general,
to the coral that we keep in our tanks as well.
Let me know down below what you feed your corals
or if don't feed them at all.
I think people can be successful in either way,
but I'd like to make the suggestion
that you'd be more successful if you do feed them.
So I hope you enjoyed it.
I will see you next time.
Bye.