Lowering Nitrates.

[Gravesj1s]

i'd love to see some hard numbers or science to back up lr rock claims. so many tanks seem to be sucessful with minimal rock. i preffer the two island aquascape over the fruit stand. all i seem to find are vague 1-2 lbs per gallon guidelines. i'm a fan of lr /just don't know if it's more hype than fact.

I dont know of any hard evidence but lets look at it from a different perspective.

If you were to run a skimmerless tank would you be comfortable with a barebottom liverock tank?I would suspect Nitrate to run higher than one ran with sediment.

 

[tmz]

Simply, advection is caused by a change in water pressure. The pressure under an object set in a flow of water is lower under the footprint of obstructing object. The speed of the flow and height of the object effect the pressure change and consequent downward flow and then the upwelling. It is discussed in some detail in The Reef Aquarium Vol 3, by Sprung and Delbeek.

The advection phenomenon is also dealt with in the design of bridge pylons since the water pressuure changes can severely undermine bridge supports. This was the big item during the design of the Beacon Newburg Bridge expansion when I was working with the NY state Department of Transportation back in the 70's and 80s. I was a regional personell adminsitrator for them; not an engineer.