Substrate questions

[jeepboy]

I have a 75g tank that has crushed coral for a substrate. It is only about 1 in deep. After reading a bunch of posts it seems that the crushed coral is not ideal and that I should have a sand bottom. My question is should I get some Southdown sand and live sand and just pour them on top of the crushed coral, or do i need to remove the crushed coral?
Thanks.

 

[aarone]

Im going to add to briggs post...
The sand also provides an area for the micro-fauna to grow safely. at the bottom layer of your sand bed there will be several anearobic zones. These zones are full of denitrifying bacteria. they convert nitrite into nitrate then into harmless nitrogen gas.
aaron

 

[jeepboy]

If I remove the CC and add 100lbs of southdown sand, how many pounds of live sand should I add? Is it ok to do this with 4 fish in the tank or will clouding the water damage them?

 

[aarone]

you can just add a cup full of LS. it does not take much to get it started up.
aaron

 

[jeepboy]

Thanks Kipass

 

[theplowking]

I removed my CC and UG two months ago. I replaced it with 40 lbs of Carib Sand and 20lbs of live sand in the 55 Gallon. My tank settled down after a week. Since the change I had no problems with Nitrates.
The whole task was about 4 hours. I did a 20 gallon water change during the removal.
I recommend removing all the CC

 

[jeepboy]

I thought I had read that the CC adds calcium back into the water which is good for corals. I currently don't have any corals but would like to add some in a few months. Do the drawbacks of CC offset this advantage?