How to know live rocks from dead rocks when purchasing ?

How to know live rocks from dead rocks when purchasing ?
cause LFS put dead and live rocks together in his tanks ...

 

Live rock is rock that has the beneficial bacteria.

Live rock can be cured or uncured: Uncured still has the same inverts and algae found on it when collected. Cured means those inverts and algae that were going to die off after collection have died off and therefore should not contribute to the nitrogen cycle.

Dry rock is what it implies rock that has not been submerged in SW with oxygen to grow the beneficial bacteria.

 

so .. how to buy live rocks ..... because i afraid i purchase dead rocks instead of live

 

If it's not in water it's dry rock.

It takes anywhere from 2 to 6 weeks to cure rock.

If it's in water asked if it's cured.

 

If it's covered in purple coraline etc then it's live. There's nothing that special about it. Dry rock with live rock will start to have the live stuff growing on it. Just don't pick out bare rock if you are paying for live.

You don't need all live rock either. I personally found a good deal on 200 pounds of dry fiji rock for my system and put maybe 10 pounds of live in to seed it. It just takes longer to have the beneficial stuff spread and grow but the end result is the about the same. Though there is less of a chance of fish killing hitchhikers etc.

 

Live rock does not have to be covered in Coralline algae, if it is then yes it is live. Any rock cycled in the appropriate SW with an O2 source is still alive even in the absence of Coralline algae.

 

True but if the cost is the same, I'd prefer buying stuff with coraline. Since it's so expensive. Also, it's insurance that the rock you are buying wasn't dry rock just put in with the live that day or something, if that store does that.

 

thanks .... i heard about methods to accelerate Coralline algae growth ... ?

 

The VERY best method is Patience.

 

Are you talking in your aquarium or the aquacultured stuff?

At home keep your mag up 1400-1500 and your calcium high and it should light off.

A LFS by me gets this pepto bismol colored rock. Looked unnatural then I found out that it's sprayed with a coralline milkshake then allowed to cure.

My willingness to spend $ per lbs on live rock depends solely on how it looks. When I can get it out of the gulf for $2 a lb and the pedigree of most rock is questionable at best.