skimmer live rock question

[harleymike]

Do you think if you run a skimmer you can get away with less liverock.
Just trying too figure out how much is enough.
My 135 gallon has almost 200 pounds.
My two 15's that are tied into the same sump have about 30 pounds. But only has a pair of clowns, and then the small angler fish going in on friday. Just added a hob skimmer to this system.
Was thinking of adding more too the 15's, if i can find some. Or is that enough with the light bioload.
I know, another friggin question from me. I'm getting close to not asking anymore. LOL

 

[yveterinarian]

The live rock and the skimmer are there for two different purposes.  The rock is to provide surfaces for the ammonia reducing and nitrifying bacteria to live on and the skimmer is to help remove any dissolved organics in your system.  The only way you can know if your system has enough to support your tank is to continue testing for ammonia, nitrites and nitrates.  If your levels of ammonia and nitrites stay down with the bioload you have, then you have enough live rock.  A skimmer that is rated larger than your tank can certainly help keep the bioburden down so the bacteria don't have to work as hard but you want to keep a good healthy amount of rock in the system whether you decide to have less in the DT and more in the sump where you can't see it, the more rock, the better for your system.  The best rock for surface area is the Eco rock or Marco rock as it is very porous and provides lots of surface area for the bacteria to adhere to.

 

[unibob]

If you are not already running pellets, these can allow you to pull some rock from system as they compensate for an area for bacteria to grow.

 

[KBennett]

If you are not already running pellets, these can allow you to pull some rock from system as they compensate for an area for bacteria to grow.

I disagree with this principle.  The whole point of live rock is that inside it are anaerobic conditions for bacteria to get rid of nitrate to be expelled as nitrogen gas.  The bacteria from your pellets won't do that since they are well aerated.  the excess bacteria from pellets take up nitrogen to grow, but don't export it from the system.  That is why you need heavier skimming with pellets.

 

[Jewel]

I think the more Live Rock the better, But certainly not at the expense of cluttering your display, Big Sump, Lots of Rock and a big ass skimmer, But as you say you have a Low Bio-load. What's the problem? High Nitrate- probably not, High Phosphate? And don't stop asking questions, I find we all need reassurance from time to time.

 

[unibob]

[quote author=unibob link=topic=7146.msg72687#msg72687 date=1386766014]
If you are not already running pellets, these can allow you to pull some rock from system as they compensate for an area for bacteria to grow.

I disagree with this principle.  The whole point of live rock is that inside it are anaerobic conditions for bacteria to get rid of nitrate to be expelled as nitrogen gas.  The bacteria from your pellets won't do that since they are well aerated.  the excess bacteria from pellets take up nitrogen to grow, but don't export it from the system.  That is why you need heavier skimming with pellets.
[/quote]

I don't run pellets currently, but know this is what people seem to do when they are looking for a bare minimal amount of liverock in system.

 

[KBennett]

I'm not saying that it doesnt take no3 out of the water, rather that it doesn't do the same thing as live rock.  The bacteria reassimilate the nitrate into proteins for the skimmer to catch. You end up having to skim more to take that nitrogen out. 
So to get to the question, yes, you can have less live rock if you add a skimmer.  The skimmer takes proteins out before they turn into ammonia for the rock to process.  It really depends on your bioload as yveteranarian explained.  There are other ways to help this process including biopellets, algae growth in you sump, deep sand beds, etc.

I have a 220 with less than 100 lbs of live rock and I've never seen any nitrates, though I have a deep sand bed and a crappy skimmer.  I don't have many fish, but my auto feeder feeds flakes 4 times a day and I tend to go crazy feeding my anemone.

 

[Neopimp]

Pellets with discharge close to a large skimmer means you can run less rock.

Rock has a part in the complete nit cycle.  Pellets grow the bacteria and the skimmer removes them from the system.