Rookie substrate question!

[fishyclown]

Ok, I warned you that I was a rookie, right?
I've spent the last two hours (is that amazing?) reading up on all kinds of stuff on this msg board since I'm new to the hobby. I was given an established tank, so it was kind of unestablished and then established again (Ha! Ha!). I realized when we were putting it all back together again that the substrate (crushed coral and shells) looked pretty thin. I just made a mental note that I would buy more substrate when I could.
Now that I've read all this info. about deep sand beds and how CC is a producer of nitrates I'm kind of worried. I only have 3 fish and 30+ small feather dusters (I'm not really counting the bristle worms I've discovered and know that I've got to eliminate). So, in a 70 gal. tank it will take a while to build up bad levels of the bad stuff, right?
I'd appreciate it if anyone with this kind of knowledge could explain to me the set up and benefit of a dsb. And if you're really in for a challenge... Could anyone explain what happens with the aerobic/anaerobic bacteria and the nitrogen cycle? I'm a 5th grade science teacher and am curios about this. Now I'll be embarassed if it's something simple that I could have figured out on my own...
Thanks for trying if you do!
Shelly

 

[mr . salty]

First off,WELCOME TO THE BOARD. A DSB is benafitial in many ways.#1 it doesnt have the nooks and crannies the cc has,so uneaten food,and fish waste will not get trapped in it and rot causing high nitrates.#2 The left over food and waste doesnt need to be vaccumed out like with CC.#3 It makes a home for anarobic bacteria,That is bacteria that thrives in a low/no oxegen enviroment.This bacteria actually feeds on nitrates and turns it into nitrogen gas that then escapes the through the water in bubbles.Thus compleating the nitrogen cycle.(ammonia>nitrites>nitrates>nitrogen gas)If at all possible,you should change the CC in your tank to a DSB.There is a product avalible in local fish stores (and in the store on this site) called NATURES OCEAN Live Sand that already has all the needed bacteria to provide a good live deep sand bed.It can be added to an exsisting/established setup without the threat of a recycle. Hope this answeres your Q's. If not,respond with more Questions.There are many people here from around the world ready to help. GOOD LUCK WITH THE TANK,AND THE KIDS. Teachers rule

 

[fishyclown]

Thanks Mr. Salty!
Can anybody tell me if these big water changes I'm doing are bad? With so few animals in such a large tank, I figured I had some room for error until I really figure it all out.
The fish never seem to be bothered by my intrusions. The percula clown fish, as a matter of fact, stayed next to my hand almost the whole time I was scrubbing the stuff in his area. The other two (tang & damsel) come out of hiding within minutes after I put all the lids and lights back on.
I've never seen ick spots or anything either to show stress. These little guys have been through a lot, and I mean a LOT, of activity in the past 2 months and if they had any ick hanging around you'd think it would have reared it's ugly head by now. Nothing new has been introduced to the tank in almost a year, but as soon as I feel like I understand it all a little better I have a few things in mind that I'd like to add.
Anyway... enough for now! Please respond if you have any answers or anecdotes about this stuff. Thanks!
Shelly