i plan to have a lot of rock. i wonder if it would be intelligent to do one or two inches of sand, for the looks? i don't want a bare-bottomed tank.

My first sandbed, 4" - not so good as far as practicality and esthetics. But, it was disturbed and moved, and was the finest grain.

Second sandbed, second tank, 3" - worked well, looked good. Larger grain size mix, different colours too. Lots of life.

Third sandbed now, ~3" with a skiff of gravel on top. So far so good. A little ugly, but seems to be harbouring the necessary life. Crabs are constantly going over it as well, and it is quite clean, has the requisite layers visible from the front, colours, bubbles, etc.

Some of the nicest tanks I've seen in pictures though, had the thin mixed substrate, almost a "grunge" look. Could we be converting to Garf methods??

:eek:

Okay, I have missed something. Could you point me toward some reading material which states LR removes Nitrates?

Thanks. :confused:

Bob, I'll try to find some material, but before the sandbed craze, that's all that was used. The anaerobic areas in the rock house the bacteria required for denitrification. My first reef tank (bare bottom) had no nitrates.
A sand bed may/will allow greater stocking capacity, but the rock will remove nitrates. This was the technology in the mid 90's.
Most reading material I have is printed, ie, older FAMA mags. I'll see what I can dig up electronically.

Some stuff here.

http://saltaquarium.about.com/librar.../aa111901a.htm

particularly the quote from Deelbeck near the bottom. Very brief, but gives you an idea of what the rock was originally intended for.

Supposedly, LR that is porous will have anoxic regions in it... Thus we should get nitrate removal.

For what it is worth I don't think a 9 inch sand bed will do any good. Stick with 4 inch, it has been proven to be the best depth for a De Nitrifying sand bed. I keep about an inch to an inch and a half in my 90 and 4 inches in my 40 gallon refugium. I have about 60 Lbs of LR in my tank and about 20 Lbs in my refugium. I do 10 gallon/week water changes and I have no nitrates.... is it the DSB or the water changes??? I don't really care, I'm just happy that I don't have problem algae, and I do have healthy corals and inverts.. (or so they appear healthy).

there have been studies that have showen that a proper DSP is more efficient in removing nitrate than LR. so does this mean we don;t need LR.. nope not in my views, what it does mean is that if the design you like calls for less than 1.5lbs/gal you can do it. I started that way but something happened and I ended up with about 2 or 3 lbs/gal :rolleyes:

Steve

Steve, we're suggesting you don't need sand, not rock.

ok well to be different let me sugest you don't need rock but you do need sand :silly:

seriously the trend which is cool seams to be a nice sand bed and small piles of rock.. this way you can actuly let the corals build the reef.

Steve

I still think you're missing the point of the discussion. We're discussing whether or not a deep sand bed is worth the trouble. There's no doubt the sand acts in reducing nitrate, what is being questioned is the long term safety of one.