Dry Rock Questions

[intarsiabox]

I am starting a new tank from scratch (29g nano) and plan on going with all dry rock to start off. The options I am looking at are the marco rock from Reef Supplies vs. the Pukani or Fiji from Eli. I am guessing 30lbs would be plenty but would like to hear what others think. Any statements on experience with any of these products such as one being better than another and why would be appreciated. Thank-you!