Live rock how much

djnzlab1 · 03-07-2007, 06:08 AM

HI,
I read another article that reccomends that a 55 Gal tank should have about 100 pounds of live rock , IS that over kill or about right if so I need to buy a bit more.
And if your using live rock for water quality it would seen that large pieces are more likely to remove nitrite than smaller elk horn size pieces cause the center of the large rock is where you find those anerobes??
Doug

jtReef · 03-07-2007, 06:16 AM

You can look at it in many ways. Some say 1-2 lbs per gallon. However if you don't like having a look that full of rock and are not going to have a large bio load you do not need to put in 100lbs of live rock. Also try to find rock that is very pours which will do a better job breaking down the nitrates from the extra surface area.

Also keep in mind if you plan on adding some soft corals many of them come on decent pieces of live rock. Thus start with about 60lbs or so and then work your way up to get the look you like in your tank.

Tangster · 03-07-2007, 06:24 AM

Oh don't buy and use L/R as a method or reason to pull down NO3's and thinking you won't have a issue with the NO3's it's use will only help to a point and a small point at that.. There are other far better better options to control NO3's Not to mention cheaper and safer ways ways Live rock is no magic bullet.. You will have NO'3 with L/R

rayjay · 03-07-2007, 08:28 AM

Like most aspects of reefkeeping, there are many ways and opinions but I'm with the live rock proponents in this matter.
I believe that the core of the tank revolves around a minimum of 1 1/2 lbs of QUALITY live rock per gallon of water. Using dense rock as most base rock is, or lesser quality live rock that isn't as porous, requires more weight in that the dense rock has less surface area for the beneficial bacteria to grow on so you need more rock to have sufficient capability of the process.
Contrary to what Tangster has written, I believe QUALITY live rock to be the best way to control nitrates. In fact, it is the ONLY thing I have to control nitrates in all of my ten systems.
Over the last 13 years, I have set up plenums, RFUGF's (prefiltered), shallow sand bed. deep sand bed, and many hybrids of these types.
For many years now, I have reverted back to my original systems of bare bottom Berlin.
I use home made skimmers and quality live rock, heaters, lights, power heads for movement, sumps, and thats about it.
I don't even test for nitrates in any of my systems, and haven't since back when I first started 13 yrs ago.
I don't know what my nitrates are, and whatever level they may be at, they certainly don't inhibit functions of my tanks.

coral reefer · 03-07-2007, 09:07 AM

Very rarely do I test for nitrates in my tank because I have many filter feeders such as big Tridacna's that feed on nitrates so if my nitrates are around .10>that is ideal for me!
As for the live rock myth, it use to be you wanted to have 1-2 pounds per gallon of water! However, their are some misconceptions that should be addressed:
First of all, not all live rock is the same in terms of density as some rock is more porous than others of similar size, therefore the weight of the more porous rock will be much lighter in most cases! This porous rock is more beneficial to a tank than the heavier rock.
If you have too much live rock, you impair your powerheads and other means of water flow from removing detritus carrying food and gas exchange between your rock and other pelagic areas of your tank. You want to try and keep detritus suspended in your water column for as long a period of time as possible for the skimmer to remove it!
Another thing to avoid is too much live rock covering up your benthic substrate area to avoid too much advection/diffusion and diminished gas exchange from bacteria etc. in your substrate! Good water flow to your substrate area will aid in this problem!!!
Large or small pieces of live rock will do the same thing-the difference is in the porousity of the rock IMO!!!

ddcengineering · 07-19-2007, 06:29 AM

Its just science.. ahah.. i have taken many science classes, (civil engineer) ... and well to get more surface area on an object with the same density ratio one should use smaller LR, since it has more surface area ratio for the size of the rock. and if you make the quantity of smaller lr to the quantity of larger lr (same density) then you would have more surface area on the smaller lr and therfor more bacteria. woot!