Live Rock Question

[Singlemalt]

If I have time this weekend I'm thinking about taking a drive down to Pacific East Aquaculture to buy 100lbs of their Tonga Fusion Rock. Before I do I have a couple of questions.

1. Has anyone purchased this rock from Dr. Mac and if so how do they like it?

2. The woman on the phone told me the rock was already cured. That's fine but don't I still need to cycle the tank somehow? In my FOWLER I used uncured rock to cycle it. Should I do the shrimp thing just in case?

Thanks
Lou

 

[Edwardw771]

Save the trip and order from Marco Rocks. his rocks are dead but are still nice.
If you want live rocks two local stores have cheap nice rocks. One is Allquatics and the other is The Hidden Reef.

 

[ken6217]

Someone enlighten me on Marco Rocks. Basically it seems like it is dead rock which is now a decoration, and you need to cycle it the same way you need to cycle your average fish tank so that the rock can becomes live? Please tell me that there is more to this than that. If not, I see a new side business for me in the future.
Ken

 

[jazzsam]

Someone enlighten me on Marco Rocks. Basically it seems like it is dead rock which is now a decoration, and you need to cycle it the same way you need to cycle your average fish tank so that the rock can becomes live? Please tell me that there is more to this than that. If not, I see a new side business for me in the future.
Ken

Exactly. It is dead rock that you are going to seed and make live rock. Not a bad idea to buy it dead, seed it, and sell it as live!

 

[harryk]

buying dead rock in most instances is the cheapest way to go, and all you need is a small piece or two of live rock and it will seed itself with bacteria and coraline algae in no time flat

Harry

 

[DaveK]

The use of "dead" rock can be a good way to go. As the others pointed out, over time it will become populated with bacteria, and over a longer period of time, populated with lots of other nice stuff.

OTOH, I got to say that the LR from Pacific East Aquaculture does look great in their display and coral systems. It sure would make a great base for a reef.

It all comes down to saving money verses saving time, and to a lesser extent, artistic appearance of the rock.

In any case, even if you don't get their rock, it's well worth a trip to Pacific East Aquaculture just to see the place, and get some really nice coral frags.

 

[ken6217]

And where's all of that beautiful life and colors. You have to bring your own? This sounds like an ad for live rock that you would see at 2:00 in the morning on cable TV with the Ginso knife and the pet rock. Oh wait, I can take my pet rock and make it alive by throwing in my tank with some damsels or dead shrimp.
Ken

 

[JohnS_323]

I was going to stay out of this but I have to say that you know not what you bash. I have seen more than my share of rock in my time and nothing AT ALL compares to the aesthetic value of Marco Rock. I liked it so much the first time I saw it that I decided a change was in order. I bought 150#'s and have it curing now. When it's done, I'm tearing apart my entire 180, which is looking pretty nice these days, and starting from scratch. All of those beautiful colors will come back in time and supporting it will be a really, really nice rock structure.

I'm certainly not trying to sell anyone one way or another, all I'm saying is there is a whole lot more to Marco Rocks than "dead decorations".

 

[Edwardw771]

couldn't agree more John. I also got 150 pounds for my 265. The reason I got Marco Rocks is because I saw the display at MCANA and man they look cool after a few months of cycling. IMO all tanks need a few months to be truely ready to be a reef tank.

 

[ken6217]

Ok, so let's bring in the argument of light porous rock versus dense rock and that the porous rock holds much more bacteria. So why are people on this forum saying stay away from dense rock, branch rock, etc, when your dried rock starts with no bacteria and will only have as much as the seeding source. Then factor in that the only bacteria that will be sustained on this, or any rock, will be proportional to their food source (waste). Beneficial bacteria without a food source will die.

I have no issue with the dry rock and seeding it, my issue is with people saying don't use too much dense rock, and to use light weight rock as you will have more surface area for bacteria. One, or one and a half pounds per gallon of any quality Fiji or Tonga rock will give you as much or more than what you will be able to seed yourself. Again anyway, a lot of this is moot since what bacteria that you have once your tank is cycled with live rock, or dead rock must be "fed" for the population to stay constant.
Ken

 

[Carlo]

Ok, so let's bring in the argument of light porous rock versus dense rock and that the porous rock holds much more bacteria. So why are people on this forum saying stay away from dense rock, branch rock, etc,

Because in all honesty you're throwing your money away. For example it might take 5 pounds of dense tonga branch rock to equal 1 or 2 pounds of good porous rock in it's ability to hold the denitrifing bacterias your tank needs. Would you rather pay $15 or $6 for the same amount of biological media?

when your dried rock starts with no bacteria and will only have as much as the seeding source. Then factor in that the only bacteria that will be sustained on this, or any rock, will be proportional to their food source (waste). Beneficial bacteria without a food source will die.

No not at all. You do not need to seed bacteria at all. Bacteria will come out of "no where". Actually/technically it's airborn. You can/will only have so much of each different type of bacteria in the tank depending on the amount of food source provided for the bacteria. For aerobic (see below) bacterial growth, all that is required is ammonia (food source) and oxygenated water.

Whether eaten or not, natural process render most food into ammonia, which can be toxic in concentration. Bacterial processes in the tank will convert this toxic ammonia into equally toxic nitrite. Other beneficial bacteria then convert the toxic nitrite to nontoxic nitrate. Actually, in significant concentrations, nitrate at best have a negative impact on water quality. These types of bacteria are known as aerobic bacteria. This "cycle" is the process that must take place in a marine tank. Cycling a tank is nothing more then building up the needed bacteria that can break down food & poop fast enough so nothing is at toxic levels.

There is yet another type of bacteria called anaerobic bacteria and it breaks down nitrates into Nitrogen which simple bubbles up into the air. This type of bacteria likes water void of O2. This is where the importance of the rock you choose comes into play. The former types of bacteria will live on the outside of the rock, sand, heaters, and other surfices and can get by with limited surface area. This later bacteria type needs places devoid of O2. With porous rock this bacteria will live deep in the internals. The former bacterias will break down the ammonia/nitrites using up the O2 in the process so by the time the water makes it into the deep crevices and porous areas it's low or void of O2 so this type of bacteria can do it's thing.

"Seeding" live rock is a way to bring in fauna and coralline algae which generally won't appear out of no where (like the bacteria). The advantage to using aquacultured or dry rock is that it's void of life (no bad critter highjackers). You can go to a LFS and buy a small rock or two covered in the exact colors of coralline algae you like. For example instead of the boring/common pink/purples you can search/seek out small pieces covered in yellow, green and oranges. Then you place this small rock(s) in front of a powerhead in the tank. The water flow will spread out the coralline spores and the coralline will grow on all your rocks assuming you have adequate light and your calcium & alkalinity levels are roughly at the proper levels.

Besides coralline algae you can also "seed" things like copepods. One company who happens to be a sponsor here at NJReefers called Reef Nutrition has a product called Tigger Pods. A small jar of this runs normally about $20 and contains live pods. Once you are done your tank cycle (no toxic levels) you can dump a bottle into the tank. With a little phytoplankton added routinely (until your tank produces it naturally) you provide a food source for these little guys and they will multiply like crazy.

Going this route with dry or aquacultured rock allows you to totally control each of these steps and allows you to control what is and isn't brought into the tank.

I have no issue with the dry rock and seeding it, my issue is with people saying don't use too much dense rock, and to use light weight rock as you will have more surface area for bacteria.

It's not so much "light" rock versus "dense" rock but the porousness of the rock. Generally speaking however porous rock is lighter. Again it's not the OUTSIDE surface area you want to concentrate on but the INTERNAL surface area. This is where the denitrifing bacteria do their work (low O2 environment) and what you want to look for.

One, or one and a half pounds per gallon of any quality Fiji or Tonga rock will give you as much or more than what you will be able to seed yourself. Again anyway, a lot of this is moot since what bacteria that you have once your tank is cycled with live rock, or dead rock must be "fed" for the population to stay constant.
Ken

There is nothing wrong per say with using dense rock if you use it sparingly. Some branch rock here and there can certainly make the tank look more interesting. I just wouldn't count dense pieces of rock as good biofiltration rock. With good porous rock you might only need 1 pound per gallon where with dense rock you might need 3 pounds per gallon to keep the chemistry (ie nitrates) down to the same level. That's assuming you keep the rock clean. Obviously the more rock you have in the tank the harder it is to control flow and keep debris out of the rock.

Sand can also do much of what live rock can do to a degree. Depending on it's application it can work with your live rock or against it.

Hopefully, this helps a bit, but it's still a nutshell overview.

Carlo

 

[Singlemalt]

So in the 120 that I am about to get going one way to go would be to get 50 lbs or so of live rock and maybe 75 lbs of Marco Rock?

 

[Edwardw771]

Marco rock is Fiji or Tonga rock. and turns live quickly. 75 Marco and 50 live would to perfect. Just make sure you cook the live rocks first so you have no hitch hickers.