Mixed ratio of live sand to crushed coral?

[cannonman]

My first tank was a live sand bed and in my opinion is by far the best. My second tank I got from somebody all set up who was sick of it and it had crushed coral which I left in it (sorry I did that) when I moved it. I know that CC can have some good buffering abilities but that LS is generally considered better filtration and better in a number of other ways. I want to eventually upgrade from a 75 gal to a 125 or larger reef tank. My question is How do you think one part CC and four or five parts LS would be for a mixed substrate? Just a thought, any opinions here?

 

[cjworkman]

Depends on what your goal for the substrate is.
Typically you either want a very very shallow sand bed, or a very deep one.
A deep sand bed 3"+ will help keep nitrates under control. Also a very shallow sand bed will keep dietrius from getting trapped in the sand and generating ammonia/nitrite/nitrate.
If your goal is a deep sand bed, then as much fine argonite sand as possible is what you want.

 

[cannonman]

A happy medium is what I was aiming for- I recently read an article that shot the deep sand bed idea all to Heck, lots of problems in the long run was the just of it in the long run. My next tank I want to put about a 3" bed in. I was considering mixing a small amount of CC in with it but perhaps that really wouldn't serve any purpose (buffering capacity?). I think in terms of look an all fine sand looks the best-

 

[1journeyman]

Aragonite sand is actually better at buffering a tank than CC. CC dissolves at pH levels too low for marine aquariums.
Fenner and Calfo maintain that a sand bed should be less than 2 inches or greater than 4 inches.
Most, if not all of the problems associated with deep sand beds are a result of aquarist error. Brisk flow, good skimming and keeping the sand bed healthy (no sand sifting creatures) along with sand shifting creatures like Nass. snails will provide great biological filtration.
A "happy medium" sand depth is usually the one that fails. Too shallow for anearobic bacteria and too deep for proper cleaning by clean up crew.

 

[cannonman]

Good info! So 3" is too shallow for aneorbic bacteria- I did not know that. Two inches seems to shallow to me... and that latest article in I think it was Fish magazine really scared me away from the deep bed idea, I would have to re read it but it made a lot of sense.. I don't know. So let's say I went with 2", with good water flow don't youn end up with some spots getting down to bare glass from time to time, also, if I went shallow would that increase the need for additional filtration to make up for the lack of aneorbic bacteria?

 

[1journeyman]

Honestly, once the bacteria starts growing on your sand it usually stays in place pretty well. Just make sure your powerheads are blowing water across the sand and not into it.
Anearobic bacteria is the final step in the Nitrogen cycle. It breaks down nitrate in to Hydrogen and oxygen (I think...). So your tank can exist without it. (The goal of a deep sand bed, besides buffering and habitat, is to complete the Nitrogen cycle and eliminate nitrate).

 

[reefreak29]

i dont know if this helps but my sand bed in my tank is 2 inches , i have a 20 gal fuge with 8 inches, 0 phos and 0 nitrate

 

[acrylic300]

I have a couple inches of CC with a 1" layer of sand on top of it. Nitrate 0 Phosphate 0 after a year...It gradually went down at about 8 months it hit 0.
I can see little critters in the spaces between the CC...through the glass.
A lot of the CC has worked it's way to the top and my tangs like to pick it up and nibble it. They are very healthy and usually have a little gravel in their poop.