[fisheyes]

I have a new 40 gal saltwater tank with 12 lbs of live rock (tonga & Fiji) Been up and running 2 weeks. How often can Add new pieces and how many lbs at a time too get my goal of 40 lbs? Thanks for any replies on this in advanced.

[glampka]

Would have been best to add it all at once. Part of the reason is that you want the rock base in first & then add your sand so that if you have burrowing fish, they don't topple your aquascape. Depending on where & the type of rock you get there will usually be die-off depending on how long it is out of the water. This will contribute to higher ammonia levels in the tank & you'll always be running through mini-cycles. IMO, get cured rock at this point & add it all at once & watch your levels.

[fisheyes]

All the rock I put in is all cured live rock so I think you assumed I put in uncured rock. So the question again is if I'm using cured rock how much at a time?

[RyanG]

I'd just buy it now and then add it all at once.

[mtfabel]

I agree with Ryan and Glampka. Its best to add it all at once, because like galmpka said everytime you add new rock your tank will go through a mini cycle, whether you buy cured rock or not. There will always be some die off.