Live Rock...Is there a point??

[Steve Richardson]

yep. I think the biggest benefit is added biodiversity. The more the merrier, and get it from different places. I'm a *big* believer in having loads of scavenging tiny critters to help reduce organic debris. I like to think in my own tiny mind that it produces a more stable, diverse, and resiliant environment. It also looks great and gives a natural look to the tank, not to mention hiding places etc.

Cripes... Sometimes the rock is more entertaining that the fish when its really crawling with life. I can be hard to believe all of the stuff going on there. sponges, wormy critters, tiny mollusks, 'pods, yeah the periodic mantis or 2, starfish, etc etc etc.

Id guess that denitrification is likely far outweighed by a good healthy sandbed, but I'm largely speculating there... both are used and both will level out once the tank is stable.

In any case.. it doesnt hurt. Dont fight it. ;-)

Cripes... I've got to put my tank back up. Its been down for a couple years now and I'm really missing it.

 

[GroYurOwn]

i agree with the opinion that the liverock is the most interesting thing in the tank. i can sit and stare for hours looking for little critters, that makes it all worth it.

 

[Dewey115]

I dont know how many nights I have stayed up for hours in the dark just watching everything on my LR with a little flashlight. I still spend a good half hour every other day or so just looking it over and around rocks and all the more hidden areas I dont see as easily when I am just normally wandering around the house.

 

[cdraughon]

My only concern with new LR is the pest critters. When I setup my tank, my wife suffered through an isopod problem. When I upgrade, I am considering "cooking" my new rock before using it. It seems this way I will still have the bacteria, but limit the chance of pests. Anyone agree with this thought?

 

[BeanAnimal]

Why bother cooking the rock? Why not just get dry base rock and cede the tank with a known "bad bug free" rock or some sand.

I have limpets, all kinds of worms and other bugs, chitons, sponges, 3 colors of coraline, and countless other critters as a result of the frags and a few rocks that others have given me (non larger than a softball) when fragging their corals. As I stated, I did not buy an premium live rock (well 1 pound and it had coraline, but little else).

 

[Agu]

But, I think at the very least I will need to read a bit more on the history of reef keeping.

Lee Chin Eng pioneered the use of "live Rocks" in the early 60's. It was touted as a more "natural" method of reefkeeping.

Here's a short history of the hobby to get you started,

A History of the Hobby

 

[goby1]

It seems to me that most life that comes on lr is considered detrimental. Bad algaes, crabs, worms, etc. What do we want other than bacteria, coralline, and pods? You can easily seed those... Other than that, it's surface area, and that can be incorporated with artificial means. I'd still get all natural myself though. I don't know why. Maybe I'm stubborn.

G1

 

[Qwiv]

I will comment on your original question mate:

It does matter how porous your rock is on the microscopic level. The more small holes the better. (A big hole does nothing) You want the water to slowly filter into the rock. This is done by a few pumping activities of worms, bact, etc. I don't remember the scientific words for this, but Bomber could answer that question for you if he was still around. You can actually measure rock pulling and pushing water in and out of itself using dyes. This is also witnessed in BB tanks.

As far as coraline algae covering up all the pours, not going to happen. Coraline algae is porous itself. Coraline algae can grow a few inches thick as it keeps growing and growing and growing. Once you rock is covered in coraline, the growth doesn't stop. It gets thicker and sometimes grows in really cool shapes.

As far as starting with liverock, that is a question for the reefkeeper. Fresh LR will establish faster, be more diverse and produce an appearance impact. You can take dead rock and seed it with life and still be successful. Just remember the population densities will be different if you do this. Since you are adding a small amount of life to an environment, the creatures introduced will populate your tank depending on what reproduces the fastest in your tank and on what you add. This will differ from tank to tank, population densities to population densities, seed life sample to seed life sample. This may or may not be a problem, it depending on your goals. I use both.

To be direct, yes the quality of the rock has been shown to have an impact on the biological filtration of a fish tank. There are a few articles I have read over the years.

 

[DavidG1966]

I am strictly talking about filtration. Not looks... What is the difference between live rock and Seachems Matrix or DeNitrate products???? Does rock biologically filtter better then synthetic biological media? Won't Matrix become Live?????

http://seachem.com/products/product_pages/Matrix.html

 

[easttn]

Odd how one of the worst creaturs has not been mentioned yet. Burrowing sponges are very common in LR and usually 100% leathel to any SPS that begin life in our tanks abve them. If you've ever seen a coral STN and broken off pieces to try and save it only to find any color other than white running up the center, you have a burrowing sponge.

LR is pretty, it gives instant gratification (except to spouses and your wallet) but there are many chances you will introduce something you won't be able to rid yourself of for years.

As you add LPS, SPS, and any other critter there will be biodiversity, just give it time.

 

[piercho]

I keep a stony coral tank with no live rock. My hard substate is concrete and I wish I hadn't used up space with that and just epoxied the coral straight to the glass. I do have sandbed.

Consider rock "cooking", rock boiling, and other means to "desaturate" rock. Why bother with live rock if you want to kill what is alive on/in it? If you don't want sand, why not just start with a synthetic media, like the thread starter suggests?

 

[cdraughon]

Tell me where I can get dead Fiji rock and I will be happy to use it for base, and seed with my existing stuff when my upgrade is complete.

 

[BeanAnimal]

Not "fiji" but the reefer rocks are some of the nicest rock I have seen.

 

[lbear]

This is a "Live rock" thread. Since people talk about dead rock, I have pictures to share.

I know this is not vendor experience forum. I will delete my post if it's not appropriate.

I got my reeferocks two weeks ago.

I also have hirocks. You can see reeferocks at the upper left coner. I used flash light. Both of them are white.

Hirock is denser than reeferocks. IMO

 

[BeanAnimal]

I prefer the less dense rock, as there is much more room for stuff to grow on it and in it.

It will all become live rock one you put it into your system. I have as much biodiversity as the guys who spent a fortune on fiji or tonga rock. I don't have the hitchhikers though. Every frag you trade will add diversity to your tank and to that of the person you trade with. It is also a reason that so many "bad" things are propogating through the hobby.

Bean

 

[icenine2005]

FWIW: I bought Haitain lettuce leaf rock. It's the lightest, most porus rock I''ve ever come across (full of teeny tiny holes).

 

[mr.wilson]

Live rock has not only micro-fauna, but macro-fauna living deep within it. Burrowing urchins and worms are commonly found deep in the recesses of aquarium rock. I value it for the qualities we are yet to discover more than the ones we can quantify.

I drill live rock in order to fit it onto a PVC "skeleton" for aquascaping. The attached photos show evidence of burrowing worms (large black nudibranch-like worms in the case of the Fiji rock in the last two pics). These diggers are looking for food, and obviously find it in the hypoxic and anoxic regions of live rock. It is a safe assumption that the bacteria that is being eaten, has a nutrient source as well.

Live rock goes through a large die-off during acclimation to captivity. This die-off is largely in the interior of the rock. I can't comment on the value of this anoxic world, but it is part of the fabric of natural and captive reefs and must therefore serve some purpose.

In order to evaluate the different types of live rock, we must first define some terms. "Porous" (or pourous as we say in Canada), refers to the texture of the calcareous structure. For the purpose of this discussion, we will call large pores "porous" and small pores "less porous" (even though they are greater in number). "Void Space", is in reference to the shape of the rock.

Caribbean rock (Haiti rock in the case of the first two pictures) has great void space and fills a large volume without a lot of weight; however, it has a tight structure with many very small pores, thus making it less porous. It almost looks like ceramic in the interior, as illustrated in the two photos.

South Seas live rock is comprised of large pores, making it more porous than Caribbean rock. Large pores are more conducive to the development of both nitrifying and denitrifying bacteria. It too has a lot of void space due to it's branch-like shape. Although it is lighter rock, it weighs about the same per volume as haiti rock. South Seas rock does however offer more external surface area, giving it more biological and buffering capacity. Fiji rock has more aerobic surface area, as illustrated in the last two photos.

I don't think you will have the same measure of success with a tank that uses "dead rock". I try to follow natures recipe as close as possible. It's a hard one to improve upon.

 

[brentp]

I used to always wonder how people with grow out tanks with no live rock managed to keep corals growing and thriving.

Until I ran my 150 gallon tank for about 6 months with corals (mostly SPS) and clams sitting on eggcrate. I also left the fish in the tank. I was paranoid that nitrates would go through the roof so I tested at least weakly with a Salifert kit. No measurable nitrates ever.

If I could figure out something that looked good to put my corals on that would not be the detritus trap that live rock is, I'd happily get rid of the live rock.

 

[mcintosh]

Mr Wilson sure covered many of your questions concerning porosity far better than I could. I would just like to add that live rock did push the care of saltwater fish forward quite a few years during the late 70's and early 80's as George Schmitt (sp?) showed the US what the Germans were doing with the information from Lee Eng. The mini-reef was born because of live rock.

However, now that we have a better understanding of husbandry for stony corals and are becoming more aware of the damage that is being done to coral reefs around the world (and believe me I understand that harvesting live rock is almost statistically insignificant in terms of destroying reefs) we as aquarists should be looking for methods outside the "box" of live rock with corals on top. As noted by brentp live rock is not necessary for bacterial population and reduction of nitrogen. In fact, an empty glass tank has enough pores on the glass surface to metabolize a good deal of nitrogen. Add the colonization of bacteria on pumps and on the corals themselves and you are beginning to see that you can have a fully functional reef without live rock.

The problem is you are missing coral substrate. Or places to place your coral. However fiberglass faux rock and cement rocks are available and can be used. In fact "my next tank" I want to try will be a large cube tank with a single giant specimen of table top acropora or something similar. No live rock, only some sand on the bottom of the tank. High flow and a seperate sump.

By the by. Keeping corals did not start and end with live rock. I worked at a pet store in the early eighties (about the time FAMA published the mini reef articles from Schmitt) and we kept elegance, hammer, and goniopora in 20-55 gallon tanks filtered with???? U/G filters. In fact my boss kept a goni in one of those tanks far longer than anyone at the time could keep them in the new mini-reefs! :lol:

I hope this little post helps answer (or keep you thinking) your question concerning why live rock.

 

[MCsaxmaster]

Wow, so this thread got a bit nutty. Haven't read most of it to be honest. In response to the original post, there isn't good evidence one way or another that our rocks either do or don't become sealed off as far as I know. There's a lot of biological activity inside the rocks though, which folks tend to forget. There are sponges, worms, bacteria, algae, and all sorts of things living deep in the rocks.

These studies examined the movement of pore-water in rock and nutrient cycling:

Tribble et al. (1990). Stoichiometric modeling of carbon diagenesis within a coral reef framework. Geochimica et Comochimica Acta. 54: 2439-2449.

Tribble et al. (1992). Hydraulic exchange between a coral reef and surface sea water. Geological Society of America Bulletin. 104: 1280-1291.

The residence times in Checker Reef, Oahu was ~2 days for water 1 m deep in the rock and ~40 days for water 2 m deep in the rock. The greater the wave action the more the water exchange, and the greater the surge (back and forth) the greater the denitrification. There have been several other studies as well. So, live rock really is contributing to the denitrification and nutrient processing in our tanks.

cj