Live Rock question

[ocgirlygrl]

How many lbs. of LR should be in a 12 galllon tank? Right now I have about 9lbs of live rock. Is that too much? or can I add more?
I have 3 fish in there as well.
1 blue damsel
1 percula clown
1 royal dottiback

 

[malounsbury]

Generally, rule of thumb is 1 to 1½ lbs of live rock per gallon of water. You could probably use a little more, but since you have some, its better than none.

 

[amandadee]

I have another thought about live rock that I haven't seen mentioned elsewhere: When calculating the amount to use, consider that the more you use, the more water you will displace in your aquarium. In other words, say you have a 30 gal aquarium, and you add 30-45 lbs of live rock, displacing maybe 10 gal of water. Now you have 20 gallons of water that you're actually working with, making your tank that much more vulnerable to fluctuations. And now that you have that much less water volume, you re-calculate that you should be using only 20-30 lbs of rock! I think the 1-1.5 lb/gal rule should just be used as a guideline, and could even be decreased for smaller tank sizes.
Just a thought.

 

[lefty]

I'll be getting my 20lbs of LR on friday for my 29g. I don't want my tank to be packed with rock, so I think 20 pounds should do nicely. I also don't want to spend another 100 bucks on rock.
-lefty

 

[woodymdt]

Amanda,
One thing I noticed when I put my LR in the tank on Monday, was that the displacement was nowhere NEAR what I thought it would be. I understand your statement and I thought the same, but as porous as the LR is, it might be possible that the displacement might not be as much as I thought before hand.