Live Rock:  Use 1 lb rock for every tank gallon.

Rock along with your sand IS literally your biological "filter" so it's important to have enough of both to do the job we need it to do.

Used in conjunction with the deep sand bed, live rock is the “other half” of Mother Nature’s “natural” biological filtration.  Beneficial bacteria lives on & within the rock just like it does on the filter cartridges of your mechanical (let’s say back hanging) power filters, thus eliminating the need for such power filters.  Make sure to build your rock structure with a fist size space between your glass & rocks all the way around the tank to allow for good water flow around your rocks.  It also creates great swim through places for your fish!

Some people think if 1 lb per gallon is good, then 2 lbs per gallon would be twice as good - right?!  NO.  At 2 lbs/gal you have very little water left due to the displacement from the rocks.  There's a healthy balance & 1 lb/gal is it.  Understand more rock weight will be added as you purchase corals, especially if they are AquaCorals corals as mine are all mounted to real rock.

There are many different rock sources but they're not all the same.  The vast majority of rock available today is dry mined on land where ancient sea beds once were.  Some companies mine too shallow so their rock harbors heavy metals & other contaminants (even though they say they're washed etc!) which will have a negative effect on your tank as these contaminants leech into your water.  I recommend using Marco Rock.

Stay away from fake colored rocks!  The coloring can also be a contaminant!  Be patient.  Your rocks will color up naturally on their own.

Rock shapes - some are better suited for building the base reef structure like bigger bulky pieces counter sunk a couple inches into the sand bed ... to ensure your reef is stable & not always falling!  Build up with different rock shapes for aesthetics but more importantly for shelving space to place the eventual corals you'll want to have.

Don't worry about creating fish swim through areas.  You will find they easily find all the spaces between your rock structure.  Again, leaving a fist size space around all your rocks not only is critical for water flow but also creates fish swim space too!

I do not recommend gluing or pinning the rocks together.  Anyone in this hobby for more than a year will easily tell you that nothing stays the same!  At some point you will want to move a rock here & there to accommodate a coral etc. so don't make anything permanent.  Just play with your rocks until they feel stable/naturally lock into place.

Lastly, try not to be too picky about how pretty your rock structure "looks" because soon the corals you place on them will either cover or become the dominant view - & rightly so!