Today on BRS it’s everything you ever wanted to know about live rock.
Hey guys my name is Ryan, welcome to another week of the BRS 160 where every week we do
our best to help you guys, members of the reefing community enjoy your tanks and find
new ways to explore the hobby.
We do that by following the set up and progression of this one hundred and sixty gallon reef
tank.
This week we are going to explore everything related to live rock starting with why we
use it, benefits of dry verses wet, discusses surface area and porosity, discuss proper
curing and finish with curing the rock for the BRS 160
In reef aquariums we use live rock for a few main purposes Atheistic appeal, habitat for
the fish and corals as well probably the most important element with filtering the tank.
Every time I explain the set up a reef tank to someone new the first thing they ask is
where is the filter?
Filter is one of those terms that has a lot of meanings in the reef tank, by definition
filtering really means removing something and there is some equipment on a tank like
filter socks and protein skimmers that are capable of removing waste from the tank as
well as filter medias like carbon, GFO and Zeovit which are capable of filtering the
water and capturing various contaminates.
In relation to live rock filtering the tank we are really talking about using the rock
and the bacteria it hosts the rocks surface to not necessarily remove elements from the
tank but instead process or convert broken down food and fish waste in the form of very
toxic ammonia into much safer nitrite and nitrate.
It’s also possible in the right conditions for the rock and its host bacteria to perform
closer to true filter by further converting the nitrate into nitrogen gas which bubbles
out of the tank and effectively removes the ammonia and its processed components from
the tank for good
However that’s rarely one hundred percent effective and isn't as well understood as
the other processes but the general concept is water travels through the center of the
rock in areas which have little oxygen where a different bacterium populates and is capable
of this last step.
How much rock and type of rock best suited for this is not something that has been generally
understood or agreed upon as of yet.
This entire process of filtering the toxic ammonia is commonly referred to as the nitrogen
cycle.
We are going to cover this and how to cycle a new tank properly in depth in just a few
weeks.
For this episode it is just important to know that the love rock more or less just serves
as surface area for the bacteria to populate on and filter your tank for you.
There are two fundamental types of live rock with wet and dry.
Wet rock comes from the ocean and has life on it including bacteria, algae, possible
a coral or two makes it as well as crabs or other critters on really fresh live rock.
Biggest advantage to wet rock is it’s the quickest method to get a tank up and running
and look established.
The surface of live rock tends to have a lot of coralline and an established biofilm which
makes it more difficult for algae common with new tanks to take hold in the tank.
It just looks nice day one.
If getting the tank up as fast as possible is a priority wet rock is your best option
There are three major categories within wet live rock with boat rock, air rock and aqua
cultured rock.
Boat rock is packed wet in a box, often with some wet newspaper and shipped from countries
on the other side of the world like Fiji on a boat.
Whole process from collection to distribution to retail stores and delivery to you is often
six to eight weeks.
For this reason they have to scrub most of the life off before packing or it will rot
in transit.
Boat rock is live in the general sense of the word but because it has been out of the
ocean for so long I wouldn't expect to see anything special on it other than some coralline.
Strange component is a lot of online vendors will have you overnight it from there which
unless the weather is extreme that doesn't make a ton of sense and kind of seems like
a waste of money.
Air rock is rock that was shipped direct from places like Fiji via plane, stops in LA where
it is routed to the distributors and then often directly to customers overnight.
This means the rock has only been out of the water for a few days and they leave a lot
more life on it with tons of Coralline algae in various colors and possible hitchhiker
corals and critters.
When someone is thinking about live rock its air rock they have in mind.
So how do you tell the difference between boat rock and air rock?
In person it is easy because Air rock looks incredible.
Ordering online it can be a lot harder to identify but one sure sign of boat rock or
old air rock is a low price of less than five bucks a pound.
It isn't cheap to fly fifty pound boxes of rock from Fiji half way around the planet
and the reason a vast majority of the live rock in the industry is shipped on container
ships.
One other option is aqua cultured rock which is various types of rock dumped in the ocean
where it is allowed to soak, often for years before it is covered in all kinds of life
and shipped to you.
The rock is almost always a calcium carbonate rock like limestone or some form of manmade
rock.
This means there is very little impact on the ocean and environment.
There is a lot of rock in the world’s oceans but we are not going to be able to keep pulling
rock it out forever so responsible sustainable solutions like this are pretty attractive.
You can get it in both boat and air deliveries and it pretty much indistinguishable from
your typical Fiji premium.
You can also get aquacultured rock from Florida which is primarily limestone cultured in the
Florida Keys.
Because it’s local many of the providers actually ship it to you in bags of water via
airport to airport which really provides an unprecedented amount of life on the rock.
As someone who has purchased this type of rock in the past I would like to mention this
type of rock comes with a lot of filter feeding organisms which look cool when you get them
but most are destined to die without some pretty advanced feeding techniques so ninety
percent of the time it is no different than typical live rock in a six plus months and
might but be worth the price premium.
Because it is shipped in bags of water and so fresh you are going to find a lot more
pest organisms like gorilla crabs, mantis shrimp, isopods, bristle worms and funky algaes.
This is where dry live rock comes in.
This is either just live rock from the ocean that has been allowed to dry out, limestone
rock or dry man made rock.
While wet live rock is the most popular with newer reefers who are often in a hurry to
get their tanks up dry rock is more popular with seasoned reefers who want to eliminate
some mistakes of the past as well constantly looking for ways to save a few bucks in this
fairly expensive hobby.
Thing about wet live rock is it comes with not only desirable live elements but often
impossible to remove pests as well.
Most common are funky algaes, aiptasia, fire worms, red bugs, parasitic snails, flatworms,
isopods and flukes.
Many of these nasty organisms cause reefers a lot of headaches hurt or kill livestock
and very commonly result in a complete tank tear down.
Once you go through the hassle of starting your tank all over you are going to do whatever
you can to avoid putting these things back into your tank again and why dry rock is so
popular with seasoned reefers.
Basically everything on dry rock can be considered safe and some curing processes can absolutely
assure that.
This means you are starting clean and the only pests that go into your tank are those
to put in there yourself, most commonly on the base of corals added to the tank.
It is unlikely you will completely avoid ever introducing any pest to the tank but starting
with dry rock will absolutely limit them quite a bit.
Dry rock is also lower cost by the pound, doesn't have all that water weight and in
most cases ships completely free which in the end can easily make it cost half as much.
This is particularly true with the pukani which is very light.
To give you an idea of value we put forty pounds of wet Fiji in this tank and this is
forty pounds of pukani.
It’s pretty obvious you only need about half as much rock to fill the same space which
makes it a lot more affordable and pretty compelling.
Dry rock is commonly available in a few different types with pukani, Fiji, shelf, branch, reef
saver and new Walt smith’s reef rock two point one.
Pukani is my personal favorite because of its unique structure and its super light so
even though it costs a few bucks more it is likely the lowest cost option out there.
Pukani is also by far the easiest to manipulate with tools to create a cool structure.
Something we will cover in detail in next week’s Aquascaping video.
Reef Saver is a dry calcium carbonate based limestone rock mind from the ground in Florida
in areas with low PH aquifers which tunnel these cool pore structures into the rock.
One of the obvious advantages here is the sustainability and lack of impact on the oceans
reefs.
The second is the ease of aquascaping the edges of this rock fit together seamlessly.
Fiji is just a staple in reefing and historically the most popular rock used in aquariums.
The Tonga shelf and branch are more specialty rocks used to create some unique looks that
meet specific desires and honestly pretty hard to work with.
A newer entry to the market is the reef rock two point one from Walt smith which is a completely
sustainable man made rock.
The difference between this and reef saver is the rock comes in a purple color which
immediately gives the perception of an established reef once it is underwater.
The darker coating is smoother and seems to be much less likely to grow algae common with
new tanks.
I was pretty hesitant with this rock at first but it has come a long way and I think this
just might be a big component of future of reefing because it really combines the benefits
of dry rock and wet rock.
It comes pest free so you know you are starting clean, the surface seems to be really algae
resistant and most of us here at BRS were really surprised how sharp it looks once it
is in the tank and under reef lighting.
One of the things people discuss a lot when they talk rock is available surface area and
porosity.
Because these basically represent the amount of area or habitat the beneficial bacteria
have to populate your tank and quickly and efficiently process the ammonia into safer
elements.
While surface area and porosity are often mistakenly used interchangeably they typically
represent very different things.
Most of the time when people reference porosity with live rock they are discussing the visual
hole network in the rock for instance visually a piece of pukani or reef saver is much more
porous than a piece of Fiji.
This visual porosity does play a role in total surface area, for instance a round ping pong
ball has about seven square inches of surface area.
This bio ball which is about the same size was designed to increase surface area and
has around twenty three square inches of surface area.
This single ball of marine pure which has all these tiny holes is visually more porous
than both of these has two hundred and forty square feet of surface area captured in this
small ball.
So to some degree it is possible to make a visual assessment on the available surface
area.
However surface area has a more impactful component that happens at the microscopic
level.
Surface area measures the total available surface and more difficult to understand.
For instance this tablespoon of activated carbon might not look like it has much surface
area and visually isn't a drastically different size than the balls we just referenced but
at the microscopic level it has a vast internal pore network which equals the same total area
as an entire football field.
That means this table spoon of carbon has over a hundred and seventy thousand feet of
total available surface area.
Hard to imagine.
To help shed some light on this in relation to reefing and the various rocks we sent out
one hundred gram samples of each rock and a sample of that marine pure bio media to
a lab to perform multipoint BET surface area testing.
Fiji and marine pure were clear winners in this regard with one point one four and one
point zero six square meters of surface area per gram.
Reef Saver and pukani and were virtually tied at zero point five one five and zero point
five one two and Tonga came in at a pretty dismal zero point one zero square meters of
surface are per gram.
This means the rock you select can have a big impact on the total available surface
area for the bacteria to populate and filter your tank.
To add one more layer to this, the surface area testing tests the surface of crushed
up rock samples we tested but doesn’t test the availability of the internal pore network
meaning how far and how easily can the water penetrate the rock which can greatly increase
the available surface area.
One of the ways to get a general ideal of how far and how easily water can penetrate
the rock and be absorbed by the rocks internal pore network is just to weigh it dry wet to
see how much water it soaked up.
We soaked these samples overnight.
The marine pure was a clear winner and was able to absorb twenty four hundred grams of
water.
The pukani three hundred and eighty, Fiji two hundred and ten, Tonga 90 and reef saver
just sixty.
So while the crushed samples of pukani and reef saver had about the same surface area
the actual rock is able to absorb over six times the volume of water which is a pretty
good indicator pukani is going to have significantly more surface area and water can penetrate
and travel through the rock easier which could possible make it a better option for those
of you looking to use the rock to convert nitrate into nitrogen gas and complete the
ideal nitrogen cycle
The real winner in this regard was the marine pure bio media.
Even though it just looks like a large block it is incredible porous both visually as well
as tested by the lab and it was able to absorb forty times as much water.
To help demonstrate the availability of this materials available pore network we glued
a plumbing fitting on the tip and ran some tap water through it.
You can see the water just flows freely through the entire brick.
Beatify of this is you can really pick any rock you want, including those minimalist
aquascapes with very little rock in the tank itself and throw some of this marine pure
or even some rock like pukani or Fiji in the sump and know your tank has ample habitat
for the beneficial bacteria in the tank.
Once you have selected your rock you will need to cure it.
Curing the rock is often confused with cycling the tank because they share some similarities
and in some cases can be done at the same time, curing is the process of getting the
rock ready for the tank and it is very different for wet and dry rock.
With wet rock there will always be some die off from the organisms that didn't handle
the transport well.
Curing wet rock starts with giving each piece a quick rinse in a bucket of saltwater to
rinse off anything dead, loose, general muck or algaes.
If the rock has very obvious decay or large patches of algae you are likely going to want
to take a brush to it and scrub it off.
These Oxo brushes work well for this type of thing.
After that it is really putting the rock in heated saltwater and allowing ample time for
whatever is going to die to do so before you start adding livestock to the tank.
You can do this in the tank itself or in containers like these brute trashcans.
Either way you will want to completely drain the tank and replace with new saltwater once
the cure is done.
The big question is how long and do you want to put light on the rock during the cure.
Without light some corals and coralline algae will die however the process of curing the
rock creates a lot of nutrients in the water which will promote algae in the tank and get
your tank off to a bad start.
I’d say this, if you paid extra for air rock or other really nice stuff you really
probably want to put some amount of light on the tank during this time but I would try
and keep it to shorter periods and lower intensity.
It is hard to say how much die off you will have but I’d say this process can take as
little a couple weeks or over a month.
Watching nutrient levels like ammonia and nitrate will be the best bet.
Once they stop rising it is likely things have stopped dying.
I you got boat rock and there really isn't a whole lot of life on it to begin with other
than small patches of coralline I think id personally cure it without light in these
brute bins to avoid any algae growth and monitor nutrients the same way.
Once the cure is over discard the water and start the tank with fresh saltwater.
Many of the old pros in the hobby will use this method and cure or soak the rock for
three to six months before using it in the tank.
That’s certainly not required to have a successful reef tank but it will absolutely
help get all the organics off the surface of the rock as well as likely allow a vast
majority of pest hitch hikers and algae to die off.
This still isn't one hundred percent effective and preventing pests but it will reduce them
for sure.
With dry rock it is very different The Fiji, pukani and Tonga are all out of the ocean
and dried out which means they have dried up organisms on them which will need to break
down during the curing process.
This is particularly true with the pukani which will often have a lot of sponges or
other organisms in it.
While these things break down, just like any other type or organics in the tank like fish
food or waste it will add nutrients to the water like ammonia and the resulting nitrate
as well as things like phosphate and yellowing color pigments.
This is sometimes confused with the rock leaching nutrients into the water during the cure but
more accurately it is just these organics breaking down that are on the surface of the
rock.
Since this rock doesn’t need light I am going to do the cure in a dark container like
the brute trash cans to prevent algae growth.
It will help speed the process up if you add some good flow in the container and heat the
water.
How long this takes is again really variable from weeks to over a month but again the best
way to identify when the cure is done for sure is to monitor nutrients like ammonia
and nitrate.
Once they stop rising and stabilize you can consider the rock cured.
Some reefers will take this a step future and do bleach or acid cure.
The bleach will help oxidize or destroy organic matter like algae and sponges and the acid
will mostly dissolve the exposed layer of the rock and loosen some of the organics like
algae so you don’t have to wait for them to break down.
There are some obvious safety issues with playing around with acid and bleach and the
main benefit is really shaving some time off the cure.
Even after this process you are going to want to continue the dry rock cure for a couple
weeks minimum in some heated salt water to allow the rock to form a solid biofilm which
will help prevent algae from taking hold.
With reef saver and Walt smiths new reef rock two point one.
We really don't need to be as concerned about the organic end of the cure because reef saver
is mind rock and the reef rock is manmade so there should be little to no organics on
either but I still absolutely recommend soaking it in heated saltwater to get any dirt or
other contaminants off.
This also gives the rock time to form that important biofilm on the surface of the rock
to help fight against algae growth.
This is particularly important with the reef saver which has a bright white rough surface
algae seems to like in brand new tanks.
The reef rock two point one however has a dark purple surface with is really smooth.
Algae has a much harder time taking hold and spreading on this surface but I would still
soak or cure it for a few weeks before use.
I’d also like to note that a lot of these curing processes can create quiet and odor
and really stink as the organics die off.
A bag of basically any type of carbon should solve that completely.
So what did we select for the BRS one sixty.
I have had a couple hundred pounds of pukani curing and ready to go for months and this
really is my favorite rock for a whole variety of reasons including looks, density, porosity,
ease of some really cool aquascaping techniques and it’s pest free but this time I think
it is time we tried something different and we are going to go with the reef rock two
point one.
I think this rock really has a future in our industry, I like the lack of organics, the
sustainability of the product, low to no impact on the oceans and I think it is going to be
the quickest way to get an attractive healthy tank up and running.
This will also give all of you a solid change to see what it looks like in and established
tank.
Since it is new and we don’t know a lot about the surface area properties of this
rock I am also going to add some marine pure to the sump by cutting the one inch slabs
to fit the entire bottom of the filtration area of the sump.
And adding blocks to the fuge area.
I chose the slabs over balls because they are easy to remove and clean when needed.
I am going to start the cure today which is just soaking it in heated saltwater with a
couple of powerheads.
Next week we will do our aquascape in the tank, add the sand the following week and
I will do a one hundred percent change before we start cycling this tank.
This is ample time to create that biofilm and get anything on the surface of the rock
off.
Next week we are going show you all kinds of aquascaping tips, you seriously don't want
to miss it so hit that subscribe button.
If you are interested in learning more about any of the products we talked about in today’s
video checkout this link for descriptions and user reviews.
See you next week with episode eleven of the BRS 160 aquascaping!