Live Rock in a Scrubber System

[Aeros]

Instead of jacking Floyd's disgusting thread :mrgreen:

Live rock is not alive, but houses a variety of life. Base rock is live rock that is devoid of life.

Live rock serves a many fold role in marine aquaria. It's primary purpose is to house the bacteria responsible for converting urea (fish waste) into nitrogen. The nitrogen cycle.

Other roles include:

living space for micro and macro fauna,while providing a safe haven from hungry fish.

Constant grazing for fish.

Hiding place for nocturnal animals.

A natural looking aesthetic.

A medium to grow corals on

Etc..

While there are many other items that could fill the same role, no commercial product I'm aware of is as efficient.

The reason: live rock is not usually rock, but coral skeletons.

These skeletons, appearing solid, grow in intricate patterns with spaces; this is more efficient than laying a solid mass skeleton. Effectively giving the animal a mass to volume ratio that allows it to grow bigger at a faster rate at less cost.

The mass to volume ratio varies from species. Some I've encountered are little better than concrete. Others are like bird bones.

The preference in aquaria is for low mass to volume. The "lighter" stuff. Firstly, because it displaces the least water. Secondly, because it has a higher (usually) surface area.

The first reason is fairly obviously desirable; the more water the more stable a reef tank is. The second reason seems a hot debate amongst some reefers so I'll elaborate.

To get the most "bang" for your buck with the nitrogen cycle, very porous LR is ideal. Though other media will suffice, only a fluidized sand reactor can top LR in surface area, and contact time/exchange with tank water.

Some argue that a sand bed can handle the urea conversion, and to some extent it can, but not on the scale of LR.

Take a typical shallow sand bed (4" or less), only the surface has any contact with the water column. In my system that equates to less that 8 square feet. A typical porous LR has hundreds of sq feet.

Some argue that a "very" shallow sand bed would work. I would call that a fluidized sand bed. Constantly shifting, and unable to support anything but aerobic bacteria, i.e., useless in reef aquaria.


Can a system be run without "live rock" on a scrubber? Yes.

Is that as efficient as using LR? Doubtful.

Can other media be utilized? Yes, but it's efficacy is limited to it's makeup.

If we could get some carbon nanotube "rock" then I feel we could surpass true LR in usefulness.

On a side note: why do people "dust off" their LR?

[dtyharry]

14828sq feet or just over 1/3 acre is the surface area of the grains of sand in a sandbed 3 x 1 feet by 4 inches deep. Figure calculated by Ron Shinek in Nov/Dec online issue of Coral Magazine. It is a mistake to say only the surface grains have any bacteria just as it would be wrong to say that the outer layer only of live rock does any filtration, but there is no comparison in surface area of the total of each grain to a similar mass of live rock.
The only reason I really said anything is because you see all the time threads stating how they had to cook their rock to kill this or that and then they put it back in and expect it to be exactly the same, whereas in reality it has now become nothing more than very expensive porous or not so porous media.
I can't remember where I saw it but they cut various samples of live rock from across the world in half to look at it in cross section. In the vast majority of cases only the first inch or less was porous, the inside was completely solid and therefore provided no benefit whatsoever.
Incidentally, the article by Ron Shimek in Nov/Dec Coral magazine goes into deep sand beds in far more detail and also allays fears of the myth of hydrogen sulphide and old tank syndrome, definitely worth a read!

[Ace25]

The only reason I really said anything is because you see all the time threads stating how they had to cook their rock to kill this or that and then they put it back in and expect it to be exactly the same, whereas in reality it has now become nothing more than very expensive porous or not so porous media.

You know how I know you have no clue what it means to "cook rock"? LOL. Cooking rock means to put it in a (rock cooking) tank with bio-media of some type from a running tank. In my case I have about 5lbs of good pest free rock out of a display tank to seed the other 50lbs+ of "nuked" rock, and I am also putting in lots of Dr. Tim's Probiotic bacteria. I see thousands of copepods and micro brittle stars, even in the rock I just put in a couple weeks ago. So, tell me again how cooking rock gives you nothing more than very expensive porous or not so porous media? To me, cooking rock gives you pest free, algae free, full of micro fauna and full of bacteria live rock, the perfect type of live rock for acting as a bio-filter. Like any "new" media, it takes time to colonize, which is the whole purpose to cooking rock, to get it seeded with life so it can be ready to use in a display tank.

[SantaMonica]

Running a scrubber to pull out P is the same as cooking.

[dtyharry]

You know how I know you have no clue what it means to "cook rock"? LOL. Cooking rock means to put it in a (rock cooking) tank with bio-media of some type from a running tank. In my case I have about 5lbs of good pest free rock out of a display tank to seed the other 50lbs+ of "nuked" rock, and I am also putting in lots of Dr. Tim's Probiotic bacteria. I see thousands of copepods and micro brittle stars, even in the rock I just put in a couple weeks ago. So, tell me again how cooking rock gives you nothing more than very expensive porous or not so porous media? To me, cooking rock gives you pest free, algae free, full of micro fauna and full of bacteria live rock, the perfect type of live rock for acting as a bio-filter. Like any "new" media, it takes time to colonize, which is the whole purpose to cooking rock, to get it seeded with life so it can be ready to use in a display tank.

Anyone else here think that is cooking live rock? (LOL!). I was under the impression what you are talking about is 'seeding'.
Cooking is where the rock is placed in pure phosphate free water which is frequently changed to leach out the phosphates etc

Anyone else disagree with me or is Ace correct to respond in this patronising manner.

[kerry]

I always understood seeding to be what Ace described as cooking. I seed all my rock in a special tank for a few days to a couple weeks or so which also has a scrubber on it. Works real nice. My seeding tank is also a tank I use to raise pods for my Mandarin. My seed rock is full of tiny stars, sponges, pod, worms ect. It not as sterile as the cooking procedure he talked about though but, it works for me.

[Ace25]

Anyone else disagree with me or is Ace correct to respond in this patronising manner.

I only respond to people how they respond to others, and since you respond to almost every thread in a patronizing manner I thought it was fitting to do the same back to you. Don't tell me you can dish it out all day long but can't take it in return. :P

What you describe is called "nuking rock", not "cooking rock". Nuking = Kill everything on the rock then rinse out the dead stuff, cooking rock is what you do after you have nuked it to make it usable in a saltwater tank again. I don't know anyone who thinks it is acceptable to "nuke" rock then immediately stick it back into a display tank, your certainly asking for major problems if you do something like that.

Phosphates are actually good to have. Just today there was an article posted showing how high phosphates = faster coral growth.
http://reefbuilders.com/2011/12/05/acro ... te-growth/

[dtyharry]

Wonderful Ace lets all grow brown spindly corals with low skeletal density.
Just because I don't always fall into the let's follow Santa at all costs category does not make my posts patronising, I think you will find more of those from the aforementioned person in reply to my posts.
It's okay to be wrong like you are with your definition of cooking rock.

[Doompie]

Anyone else disagree with me or is Ace correct to respond in this patronising manner.

I only respond to people how they respond to others, and since you respond to almost every thread in a patronizing manner I thought it was fitting to do the same back to you. Don't tell me you can dish it out all day long but can't take it in return. :P

What you describe is called "nuking rock", not "cooking rock". Nuking = Kill everything on the rock then rinse out the dead stuff, cooking rock is what you do after you have nuked it to make it usable in a saltwater tank again. I don't know anyone who thinks it is acceptable to "nuke" rock then immediately stick it back into a display tank, your certainly asking for major problems if you do something like that.

Phosphates are actually good to have. Just today there was an article posted showing how high phosphates = faster coral growth.
http://reefbuilders.com/2011/12/05/acro ... te-growth/

I seeded (or coocked in your words) my tank with 2 pieces (3kilo's) of realy fresh live rock, which hasn't been in any aquarium. Fresh from import directly into my scrubbed tank. That worked out pretty good..rest of the rock is about 28 kilo's of nuked rock..

To use rock from an already excisting aquarium, depends on the system used on that tank.
For instance, a skimmer based system doesn't have a rich decomposers culture, because things don't get a change to rot. But you need a solid decomposers culture in your scrubber tank.
That's actually the main reason why I bought fresh out of the ocean rock. Other advantage is i like the weeds and algae on the fresh rocks, couple of red weeds still live in my display tank..looks nice.
Also there are a lot more living things in there which otherwise would never survived the cycle of a skimmer based system..so i'm very impressed by the ATS so far, i've seen things I never saw before in an aquarium..

Oke you will not have as much copepods in the beginning, but my scrubber started delivering them after < 1 month.

[zhewitt04]

I love a good pissing match! HAHA