Live rock is the base of our reef tanks, just like the reef matrix is the base of wild coral
reefs.
In science, live rock is called the reef matrix - it’s where fish sleep, where they hide
from predators, where some of them lay their eggs, and all in all a critical part of a
coral reef.
Hi guys and girls, I’m ReefMan and this time it’s all about aquascaping reef tanks!
In our aquariums, live rock provides the bulk of our filtration.
Though it looks like a solid bit of rock, it’s actually a porous substrate that gazillons
of bacteria live on, in, and around.
As water flows through and around the rock, those bacteria absorb all sorts of chemicals.
To a large extent, live rock is the reason reef tanks don’t need actual filtration.
They only need flow.
What kinds of rock are available to use in our aquascapes?
Natural rock, which was collected from the ocean.
Maricultured rock, which starts as dry rock on land, but gets dumped into the ocean for
a time for bacteria and stuff to colonize.
Quarried rock, which is what I used and that comes to you as dry rock.
Synthetic rock, which is available in a variety of shapes and colors and gives the most control
over your aquascape.
Rock comes in a few different general shapes.
Rock in nature is just old coral.
As coral grows it begins to shade very old parts of the colony, which might die and become
live rock.
A storm could break off chunks of colonies, all becoming lodged in the reef matrix and
becoming part of it over time.
Keeping in mind how live rock forms in nature, you can get it in pretty much all the shapes
that coral might grow in.
Normal rocks, boulders, sort of what you think of when you think of a rock.
This is the most common shape for live rock, and you can use a chisel to shape it to your
needs pretty easily.
Branch rock is another common shape.
It works great when trying to make a “floating” aquascape, as you can zip-tie branches together
much easier than trying to attach rock otherwise.
It’s formed from massive coral colonies broken up by storms.
The final common shape for live rock to be is in a shelf format.
This is also a common growth form for Acropora and other corals to grow in, and it forms
when these colonies die for whatever reason.
It works ideally for overhangs and things like that in our tanks.
How much rock should you buy for your tank?
This is really up to you.
As a rule of thumb, I’d suggest starting with about a pound of rock per gallon of water
in your reef tank.
That’s about zero point one kilos of rock per liter.
You might find that you want more rock, and you can always buy more, but this would be
a good starting point.
Remember that your rock is only the base, and that corals will grow at least several
inches above the rock over time.
It will help you to draw out the dimensions of your tank on cardboard or some plywood,
so that you can play with your rock outside of your tank.
It’s much easier to work with rock dry before you add it to your tank.
Flow is critical in a reef tank!
Don’t build a solid wall or pile of rock.
Make sure water can flow in between the rocks and the walls of your tank, and your fish
will also enjoy the nooks and crannies.
With that in mind, should you leave some space at the back of your tank between the rock
and glass?
Some space can help you with cleaning, but it’s not technically required.
If you have a tank without much space front to back, leaning some of your rock against
the back wall can increase the open water that fish have for swimming.
Leaning rock against the back also makes caves and spaces where fish will swim and sleep
in between the rock and your tank’s back wall.
Remember though, flow is critical, and too much rock stacked up can reduce flow leading
to dead zones that collect fish poop and stuff like that.
You’ll want to create lots of little caves, overhangs, and visual breaks in your reef
tank.
This helps break up fish territories, and it helps more cautious fish feel more at home
when they have hiding places nearby.
The impossible is possible with zip ties, acrylic rods embedded into the rocks, pvc
supports, reef cement, and cyanoacrylate glue.
If you’re using zip ties, I’d recommend following them up with some cement or super
glue as they tend to break over time.
When attaching rock with super glue or cyanoacrylate it helps to buy very thin glue, and then use
a little bit of damp sand where you want the glue to end up.
Soak the sand with glue, which is why you want the thin superglue, and hold it for a
couple minutes in place for the glue to harden.
Do this a few times to build up the joint, and you’ll have the rocks permanently joined
together.
A good source of cyanoacrylate glue is GlueMasters.
You want the thin glue.
Really, when it comes to your rock work, the only constraints are your imagination and
the dimensions of your tank.
Think about the coral you want, and how it will grow.
Shelving Acroporas will grow out from a vertical rock wall, but most Acropora would look unnatural
there.
You’ll want a lot of flat areas where you can mount coral at all levels of your tank.
Zoanthids and Chalices might enjoy the lower levels of your tank, while bushy Acroporas
would love the top.
Shelving corals could be placed in between, where they’ll grow up and out from the more
vertical rock faces you mount them on.
Some folks even create aquascapes that extend out of the top of the tank, and then grow
plants like Tillandsias or Mangroves amongst the rocks at the surface of the water.
If you’re permanently joining rock outside the tank - keep in mind that you need to move
all that rock into place inside your aquarium.
It’s easy to join several rocks and end up with something that won’t fit through
the gaps in the top of your tank, or that weighs so much you can’t easily raise it
up and then down into place in your tank.
You need to be able to move all your rock once you’re ready to place it in your tank,
and you need to do that without breaking your creation or scratching the glass of your reef
tank.
It also helps to buy some heavy duty nitrile or latex exam gloves for this work.
Superglue and reef cement gets everywhere, and rock can be sharp and abrasive on your
fingers.
Your skin will thank you for the investment in some gloves!
Look around for inspiration on forums like Reef2Reef.
Your aquascape is going to be a unique creation of your very own.
Think of it like art.
Enjoy the process, and don’t let yourself be constrained just because I say you need
lots of flat spaces for coral.
If you want a tank full of vertical drop offs, then do it!
You can make anything work.
Design the aquascape of your dreams, and really, I think the more “out there” you make
your rock work the more it’ll stand out over time against all the people who are just
piling up rock in their tanks.
Have any aquascaping tips or tricks for us?
Share them in the comments down below.
Link your tank if you have a build thread.
I’d love to see your tanks!
If you’re new here, welcome!
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Thanks for watching.
Stay safe, be kind to each other, and have a fantastic 2022!
Bye!