Difference between base rock

[stonepran]

I have about 10lbs of LR in my new tank which just started. I'll need to add another 20-25lbs and I'm thinking of just adding base rock to save some money since I already have some LR that will seed the tank. My question is that I can buy this "base rock". Another option is I have a bucket of ROCK, which used to be LR in another tank, that has been down for over 1 year. So we have 1 bucket of 40LBS of dead rock (which used to be alive) and then "base rock" for sale at the store..

 

Could anyone perhaps explain any difference, and the best way going about adding either.

 

 

Thanks

[Satchmo]

Base rock is live rock in terms of having living colonies of bacteria in it. It just lacks the lifeforms and coralline coverage that the good stuff has. Dry rock is, well... dead. Treat base rock the same way you would LR -you have to cycle it. Dead LR is fine to add, but you won't get the benefits of additional filtration until it can be colonized with bacteria. Since you already have a good 40lbs of the dry rock, I would just go ahead and add that. Just bare in mind that you'll have to stock slowly to allow the rock to re-establish itself. Several months down the road, with good Ca and alkalinity management, you won't be able to tell the dead stuff from the LR.