All About Liverock

[Krish]

One of the most important things you will ever have in your tank that plays a MAJOR role in your biological filtration and denitrification is your liverock. In a nut shell, all live rock is is what it's name states...Rock that is "alive". Alive in the sense that it is teaming with many beneficial life forms and organisms like sponges and tube worms which are great filter feeders, crabs and worms that can also be benefical in some cases as well as the all important different strains of bacteria that will biologically "filter" your tank. Your rock will form the foundation of your tanks biological filtration and therefore is something in all cases, you want to include in your system. Due to it being so pourus, it provides tons of surface area for the necessary aerobic bacteria and anaerobic bacteria to colonize...Aerobic being those responsible for converting ammonia produced from waste, un-eaten food etc into nitrite, and nitrite into nitrate and anaerobic bacteria which is responsible for denitrification which is simply the conversion of nitrate into nitrogen gas which is then able to be removed from your system. Simply put, this is the nitrogen cycle at its best which takes place daily in our aquariums making it possible to keep all of the nice fish and corals we all want. Apart from it's biological properties, your liverock will provide a natural habitat for your other marine life giving places for fish to hide and graze on and so forth etc.

Here is a picture of some of the life forms you will find on your liverock. If you look closely you can see a few tube worms, tunicate sponges as well as some nice colorful coraline that adds a bit beauty to the tank as well as some purpose.







With that said, let's take a quick look at the types of liverock (or rock) that is available to the reefer and the pros and cons to each.

Base rock

This is basically dead rock. Could have been once "live" rock, but all life on it is now dead leaving behind nothing, but a mass of rock with no life or bacteria in it. It can also be man made rock which is becoming quite popular as of late. An advantage with going with this type of rock is for one, it is usally cheaper than liverock. Secondly, you are ensuring that you aren't adding any bad hitchhikers, parasite or even diseases into your tank that could have transferred over from where ever the rock came from. In addition to that, you don't have to worry about transferring any un-wanted nuicance algae that may have come on the rock. A disadvantage to using base rock though is that you are starting out basically from scratch without any of the beneficial bacteria you will need to aid your system in biological filtration and de-nitrification as well as you will be starting out without any of the beneficial life forms like tube worms, the pretty coraline algae everyone wants etc. You will have to introduce these things into your system manually.


Cured and Un-cured liverock

Liverock itself is usually purchased or obtained in either a "cured" state or "un-cured" state. Here are the differences

Cured Liverock - This is usually the most expensive type of liverock/rock you will purchase. The reason why is because before you purchased it, either the LFS or whoever is selling the rock has put the rock through a "curing process" which would be to remove any of the dead or dying organisms, organic matter etc from the rock before you purchase it. This is usually done in a holding tank of some sort with ample flow, heater, skimmer etc that is carried out for a few weeks giving whatever is going to die off time to die off and be removed before you purchase it. During this time, they monitor ammonia, nitrite and possibly even nitrate doing frequent water changes and once test come back that there are no more ammonia and atleast nitrite present in the water, then it is considered cured and good to go. What this does is gives you a headstart on setting up your tank and completing your initial cycle as you won't have the long process of curing your rock as it was already pre-cured for you. Nonetheless, you will still probably have a bit of die-off during the tranport of the rock from wherever you are getting it to your tank, but nothing at all compared to what you will experince had you gone with the next type of rock which is..


Un-cured Liverock

Un-cured liverock will be a bit cheaper than cured as you are basically buying the rock straight out of the ocean without anything having being done to it. The curing process as explained above, you will now have to do carry out yourself which is why it costs a bit less as well as the reason why your tank's cycling process using un-cured rock will be a much longer process than had you started out with already cured rock.

So with that all said, it is a bit of a toss up...You can either go with the cured rock that saves you a bit of time and energy, but costs a bit more or you can opt to be a bit patient to buy the cheaper un-cured rock and cure it yourself or you even have the option to go with some base rock and seed it yourself. The choice is yours and to be honest, no matter which route you take, they can all end up with you having a successful aquarium. All it takes is a bit of time, patience and knowledge to get it done properly.

If you would like to view our liverock gallery, please visit click If you would like to view our liverock gallery, please click HERE

 

[Krish]

Once again my point of view and if anyone feel they can add to the topic or if I missed anything or even stated something in-correctly, please feel free to chime in. All in an attemp at helping out those new to the hobby.

 

[DTECH07]

Nice write up, I just finished Curing 50lb of shipped LR to ensure that ALL die-off was gone. Clear, Crisp, clean, with no caffine:bounce:. Thx

 

[Krish]

Haha!! Sounds good!! I went ahead and edited the first post adding in a link at the bottom as well as two photos from some of my old tanks.

 

[user 2204]

Very nicely written Krish and lots of good info too.

 

[Krish]

Very nicely written Krish and lots of good info too.

Thanks Alex...I was hoping I did a good enough job explaining it!

 

[Sculpin]

Great post! I've been thinking about building my own rock formation with pond foam and some dead rock I had in my tank a long time ago. Once I have all the pieces glued together in nice shape, what steps should I take (if any) to get the dead rock ready to go back into the tank and begin the curing process? The only skimmer I have is on my tank, so wondering if it would help to put it in some warm salt water with a mechanical filter for a week or two?

Also, how long should I wait before I start transferring corals over to the new rock formation? Do I need to wait for signs that the rock is alive (e.g. coralline algae) or can I start gluing corals to the new rock immediately?

 

[mojoreef]

Great write up Krish! On the nitrogen cycle though it does not quite work like that though also the P cycle is another concern.

Mojo

 

[Krish]

Great write up Krish! On the nitrogen cycle though it does not quite work like that though also the P cycle is another concern.

Mojo

Yea, I started to get a bit into the nitrogen cycle when I initially started the article/thread and it was getting a bit long so I cut it down to just the basic's on liverock (slightly touching the nitrogen cycle) and figured I'd do a seperate article later on the nitrogen cycle. However, seeing you brought it up, might be good idea to just discuss everything here instead. We can get a bit deeper into the nitrogen cycle and as you mentioned, where phosphates falls into the mix here.

Great post! I've been thinking about building my own rock formation with pond foam and some dead rock I had in my tank a long time ago. Once I have all the pieces glued together in nice shape, what steps should I take (if any) to get the dead rock ready to go back into the tank and begin the curing process? The only skimmer I have is on my tank, so wondering if it would help to put it in some warm salt water with a mechanical filter for a week or two?

Also, how long should I wait before I start transferring corals over to the new rock formation? Do I need to wait for signs that the rock is alive (e.g. coralline algae) or can I start gluing corals to the new rock immediately?

Thanks!! .

Now, as for your little project, it sounds like a pretty cool idea!! I would imagine that if you are using base rock then there is no curing you'd have to do. Curing is more concerned with liverock not base rock as there is nothing there to die-off with base rock so you can just toss it right in. If you are starting from scratch with this base rock and nothing else (ie liverock, live sand etc), then I'm afraid, you will have quite a while to wait before adding in any corals. You will need to seed that tank and start building up your bacterial populations/colonies first before adding in any corals. There are many ways to seed the tank like tossing in a piece of raw shrimp and letting it rott or getting some liverock and toss it in there to seed or whatever...Whichever route you take, you will need to let your tank mature a bit becoming teaming with all the benefical bacteria you will need to biologically filter your tank and you can monitor things by doing water tests on stuff like ammonia, nitrite and nitrate during this time. You will look out for spikes in ammonia first then as it starts to drop off you will see nitrite begin to rise and spike and then that will start to fall off and then nitrate will begin to rise a bit. The way I do it when setting up a new tank is I wait till both ammonia and nitrite have spiked and when the two no longer show up on either of their respective test kits for atleast a week, then I consider the initial cycle to be completed and then begin to add in the most hardy of fish ONLY a little at a time and allow the tank to adjust once again which will be to the new bioload. This process I repeat over and over as I add in more life to the tank because with every addition, the tank will have to adjust to the increased bioload. It isn't until I see nitrates have dropped off to zero before I even consider adding in any corals. Some may do it differently and will recommend a different route, but that's they way I like do it . On an old setup of mine, it took 9 months from start up till the first coral went in and that's because that's exactly how long it took for my tank to work off all of the nitrates and what I would call, "find it's balance". That's what it is all about..Finding the right balance in your tank.

Well just a few personal thoughts of mine again. As always stated, many ways to go about things in the hobby and be successful so ask around a bit and see what other advice you get on it and choose the path you feel fits you best.

 

[Sculpin]

Thanks, it sounds like I'll be building my rock formation with base rock, so I won't have to worry about die-off. My overflow is in the middle of my tank, so it splits the tank in 1/2, so my plan is to remove all the corals from one 1/2 and pile them up on the other 1/2. I'll then remove most of the old live rock from the side cleared of corals and put in my newly built formation. The fact the other 1/2 will be full of corals and live rock, I'm hoping the new formation will mature quickly. Once everything looks healthy on the first 1/2, I plan do to the same thing on the other 1/2. With this approach, do I still need to track for spikes (ammonia, nitrite and nitrate)?

From your post it sounds like you held off introducing corals to your tank until it was done cycling. Is it safe to attach corals to dead base rock, or do you really want to wait until it becomes live rock? Maybe another way to ask my question is do I need to worry about the base rock cycling and damaging any corals in the tank, or will the base rock simply flip to live rock if it's in an already established tank with live rock?

Thanks!

 

[Krish]

Oh, if you are adding truely dead base rock with nothing in it that could die off to an established aquarium then I don't think you have a thing to worry about. Your rock will just become teaming (bacteria wise) with what it needs to help support your tank. I thought you meant completely starting from scratch with just base rock in a new tank. If you remove some of the old live rock though to make space for the new base rock then you may have it a bit of a cycle as you will be removing some of the bacteria your tank was depending on for it's biological filtration so it will now have to re-build these bacterial colonies and find it's balance once again.

 

[Krish]

Great write up Krish! On the nitrogen cycle though it does not quite work like that though also the P cycle is another concern.

Mojo

So...It looks like Mikey is fishing for us to dig a bit deeper on this. I'll bite a bit and get the ball rolling a bit more here.

Explained simply, we are taught that waste produces ammonia. Ammonia is broken down by aerobic bacteria in our liverock which then converts it into nitrite. Another aerobic bacteria then breaks nitrite down and converts that into nitrate and then lastly an anaerobic bacteria comes in and performs denitrification ridding our tank of nitrates in the form of nitrogen gas. I've got that about right...Right?? So does it actually work like that or does something else actually go on in our liverock??

 

[mojoreef]

No not really fishing Krish and your discription of the nitrogen cycle is mostly correct with the exception of a few things.
In our tanks we are looking at dealing with mainly detritus/waste and excess food and so on and the bacteria involved in the nitrogen cycle will deal with the nitrogen based products of the baove noted. But we have to know that our tanks are not like the wild and thus it doesnt quite operate the same way when it comes to the nitrogen cycle.
So heres the quick and dirty.

As you mentioned bacteria in the oxygenated areas of LR and/or LS begin the process by using oxygen to respire and then reduce ammonia to nitrite and then Nitrite to nitrate. This process requires oxygen as the bacteria that perform the process use it for respiration. SO in our tanks we will see this in the top layer of sand and in well oxygenated areas of the LR. From this point reduction is done by different bacteria strains that create a enzyne that will further reduce Nitrate, but this enzyne will not occur in the presence of oxygen, so thus we find these bacterias in areas devoid of oxygen in areas we refer to as anaerobic. The concept from here is that these bacteria reduce nitrate to nitric oxide then to nitrious oxide and then denitrogen gas which then off gasses out of the tank.
But in our tanks this only occurs for the first few months. What happens is that a tank with any real kind of bioload will overwhelm the process, so you will have ammonia present through out. The presence of ammonia will inhibate the first enzyme in this nitrate reduction pathway so insteed of the gasses being formed it simply converts the nitrate to ammonium and then sends it bact to the top of the nitrogen cycle to be cycled again. So you never really get any kind of export from it, it just keeps recycling it until its left with an end product that it cant cycle any more and then sinks it.

So in LS the end product sinks and bigins to fill but in LR its a bit different. Since their is no bottom to the rock, Bacterial actions (creation of enyzmes, biol films, acids and so on) actually push the end product from the LR. In the hobby we call this shedding, you can see it yourself if you put some LR in a dark container with flow and heat and do not feed it. Even though their is no input you will find detritus being produced on the bottom of the container for weeks and even months after the fact.

Anyway thats the way LR deals with the nitrogen cycle, but thier is still the P factor! :0

Mojo

 

[Gort]

One quick question. Does cured live rock - transported from my LFS directly to my new tank as seed (along with live sand) for base rock - require light during the initial cycle? The live rock is covered with purple coralline and I was wondering if that would die off without sufficient light.

 

[Krish]

But in our tanks this only occurs for the first few months. What happens is that a tank with any real kind of bioload will overwhelm the process, so you will have ammonia present through out. The presence of ammonia will inhibate the first enzyme in this nitrate reduction pathway so insteed of the gasses being formed it simply converts the nitrate to ammonium and then sends it bact to the top of the nitrogen cycle to be cycled again. So you never really get any kind of export from it, it just keeps recycling it until its left with an end product that it cant cycle any more and then sinks it

So with this said, what we've been taught and what has been thrown around in the hobby for so long is kinda false when it comes to "nitrate reduction" in our tanks via denitrification where liverock is concerned. Denitrification isn't what is causing us to read un-detectable nitrates on our test kits, but rather the the conversion of nitrates back to the beginning stage of the cycle as ammonia. SO what we have is the cycle repeated again like this (ammonia ---> nitrite ---> nitrate ---> ammonia ---> nitrite ---> nitrate --> etc) rather than what we thought which was ( ammonia ---> nitrite ---> nitrate ----> nitrogen gas) . I guess the reason why we never read any traces of ammonia or nitrite either on a cycled (or better yet a mature tank ) eventhough the cycle is being repeated over and over as both ammonia and nitrite are continuoulsy being produced, is because the aerobic bacteria responsible for converting ammonia and nitrite are so efficient at what they do, that it makes quick work of it once it is presented to the bacteria???

 

[Krish]

One quick question. Does cured live rock - transported from my LFS directly to my new tank as seed (along with live sand) for base rock - require light during the initial cycle? The live rock is covered with purple coralline and I was wondering if that would die off without sufficient light.

IMO, if you have truely cured live rock, then you shouldn't have much of a cycle as there shouldn't be much to really die-off other than what might die off during transport so honestly, I see no reason why you couldn't run your lights for a few hours a day if you wanted to. All the nasty algae etc people want to die-off during their curing process should already be done granted the rock is what they say it is...Truely cured. The base rock itself definately won't have any die-off because it never had any life to begin with. I've always cycled my tanks with a some sort of lighting everyday regardless. Some people do and some don't. I'd think if you didn't run any lighting coraline may fade away a bit depending on how long you go, but I would still think it would probably bounce back once light is introduced once again. I'm not 100% positive on that as I never cycled a tank without some sort of lighting each day so I guess someone else will have to chime in on that.

 

[mojoreef]

So with this said, what we've been taught and what has been thrown around in the hobby for so long is kinda false when it comes to "nitrate reduction" in our tanks via denitrification where liverock is concerned.

No not really Krish the nitrate is still being reduced. The only change is that because ammonia is present is does not allow for the protien the bacteria require to turn it to a gas, so instead it turns it into ammonium (which is not harmful to our critters) and then recycles it again, so further reducing it until theirs nothing N left to reduce.

In the early stages of our tank, including the first nitrogen cycle. We will get the cycle as you mentioned. I am sure most folks remember seeing tiny bubbles comming out of their sand and rock (not so much rock as it is never that fresh) but as time goes by the bacterial system in the bed/rock get overwhelmed and their is traces of ammonia and nitrite through out the sand and inner working of the rock. With that the cycle shifts slightly and changes from a final gasious product to ammonium and starts over.

The concepts of denitrifaction are the same in sand as it is in rock, its just that sand is better at it as their is more surface area for the bacteria to populate, the downside for the sand however is that their is a bottom on it so the end product has no where to go. In the wild we have surge flow and waves that take and thus refresh the sand and take the detritus out to deeper depths and then allow it to fall out, this is what we call marine snow and we see on documentaries as divers swimming with what looks like snow falling all around them.

What is slightly more worring about the LS and or LR is the phosphate they produce naturally. This can be a bear for alot of reefers.

Mojo

 

[mojoreef]

One quick question. Does cured live rock - transported from my LFS directly to my new tank as seed (along with live sand) for base rock - require light during the initial cycle? The live rock is covered with purple coralline and I was wondering if that would die off without sufficient light.

Just to add to that, your always going to get a bit of die off in transport unless you are very cautious about letting the rock see air. But its not a big deal is the rock is cured. Most folks worry about the algaes diesing off and concider it to be the main thing but it is actually the sponges that live in and on the rock itself that are the main die off from live rock. With some sponges a mere air bubble can cause them to die.

Mojo

 

[Krish]

No not really Krish the nitrate is still being reduced. The only change is that because ammonia is present is does not allow for the protien the bacteria require to turn it to a gas, so instead it turns it into ammonium (which is not harmful to our critters) and then recycles it again, so further reducing it until theirs nothing N left to reduce.

In the early stages of our tank, including the first nitrogen cycle. We will get the cycle as you mentioned. I am sure most folks remember seeing tiny bubbles comming out of their sand and rock (not so much rock as it is never that fresh) but as time goes by the bacterial system in the bed/rock get overwhelmed and their is traces of ammonia and nitrite through out the sand and inner working of the rock. With that the cycle shifts slightly and changes from a final gasious product to ammonium and starts over.

The concepts of denitrifaction are the same in sand as it is in rock, its just that sand is better at it as their is more surface area for the bacteria to populate, the downside for the sand however is that their is a bottom on it so the end product has no where to go. In the wild we have surge flow and waves that take and thus refresh the sand and take the detritus out to deeper depths and then allow it to fall out, this is what we call marine snow and we see on documentaries as divers swimming with what looks like snow falling all around them.

What is slightly more worring about the LS and or LR is the phosphate they produce naturally. This can be a bear for alot of reefers.

Mojo

Ahh...Gotcha. Not sure why, but for some reason I thought you said the nitrate turned back to ammonia not ammonium. . I need to start reading things a bit closer.

So on to the phosphates...Unfortunately it seems liverock cannot process phosphates in the same way as it does ammonia, nitrites and nitrates so therefore I'd assume it is useless when it comes to phosphates. It almost seems like without good husbandry, skimming, mechanical filtration etc that liverock can actually add to a phosphate problem because if I have it correct, as the bacteria processes ammonia, nitrite and nitrate, the rock sheds as a result which is where detritus comes from and any detritus allowed to sit in the tank and not removed, only increases phosphate levels. So am I heading in the right direction on that or off base a bit again??

 

[ac7av]

Mojoreef
I know this thread is about live rock but can you describe in more detail about the phosphate and how its cycled into the system. I believe this is a problem I have been having and am having today. Also you were talking about bubbles on the rock and sand. What are the bubbles? I get them on my rock in the evening time every day. About he time I turn off the MH lighting and just have the PC lights on.