Live Rock Confusion

[earlyriser]

I'm doing a lot of research in preparation for my first saltwater setup. I've picked up two books, The Conscientious Aquarist, and The Simple Guide to Marine Aquariums (Jeffrey Kurtz). Based on them, and lots of questions I'm a little confused about live rock. A local aquarist who I really trust, said a 55 gallon FOWLR needed about 20 - 25 pounds of rock minimum. I was in Vancouver last week, and the staff at J & L Aquatics recommended 35 - 40 pounds. The guys at King Ed's said 40 or 50, a couple of guys on this site said one pound per gallon. The simple guide says live rock is largely unneccesary in a fish only system (I am using the largest Filstar cannister as well).

So far I plan to go with a fifty pound box from J & L. Sound right??

[TheGr8Blade]

Sounds GREAT to me, you can always add a little more later on if needed but must be added slowly due to die off (ammonia spike) especially if the fish are in the tank at that point.

[earlyriser]

Thanks for the reply. I'm still unclear about whythe live rock is needed. I keep several freshwater tanks, some of them heavily stocked. (Festae pair 12' & 9" in a ninety gallon) Water changes and a couple of HOB's and it's all good. What's the difference with saltwater systems?

One more question. I'll be getting this rock brought back to Edmonton with a family member (I plan to get it from J & L Aquatics in Burnaby.) We can keep it submerged for the drive. Staff at J & L said that would result in very little if any die off. They also said the normal shipping method (Wet newspaper) causes some die off. When I asked about curing they suggested I let this small amount of curing take place in the tank. Sound right to you?

Again thanks, I have tons of questions and they're all probably pretty basic, but I want to do this right! It's costs a hell of a lot of dough!

[midgetwaiter]

You don't need live rock at all.

Live rock helps as it acts as bio filter, that's it no magical powers. More is probably better but in your case too much could leave to issues.

When you see reef tanks that rely completely on live rock for their bio filtration (where the 1 pound / gal rule comes from) they are always crawling with little crabs, snails and bugs that help keep the tank clean. In many predator tanks you cannot keep as many inverts without them getting eaten so that much live rock can actually turn into a huge detritus trap and cause you grief. If you have fish that eat most inverts like puffers this can be a real big issue.

What I would suggest is get as much rock as you can comfortably afford, AFTER you buy a couple of good powerheads. Your canister will not move enough water around to keep your tank healthy by itself. Even in a fresh water tank canisters are not always enough for water movement, with heavier, harder to move saltwater, it just won't be sufficient. Get yourself a couple sieo 620s first then worry about live rock.

Thanks for the reply. I'm still unclear about whythe live rock is needed. I keep several freshwater tanks, some of them heavily stocked. (Festae pair 12' & 9" in a ninety gallon) Water changes and a couple of HOB's and it's all good. What's the difference with saltwater systems?

One more question. I'll be getting this rock brought back to Edmonton with a family member (I plan to get it from J & L Aquatics in Burnaby.) We can keep it submerged for the drive. Staff at J & L said that would result in very little if any die off. They also said the normal shipping method (Wet newspaper) causes some die off. When I asked about curing they suggested I let this small amount of curing take place in the tank. Sound right to you?

Again thanks, I have tons of questions and they're all probably pretty basic, but I want to do this right! It's costs a hell of a lot of dough!

The main difference with saltwater is that you need 5X the surface area for bacteria populations as they are much less efficient. The fish themselves are also much more sensitive to poisoning by nitrogen compounds and the extra critters you get with the rock help lots. You can keep predator tanks without live rock, just get another canister the same size as you have now and be really careful.