[pogodzib]

Most people with reef tanks aim for around 1.5 Lbs of LR/gal of water, so you may be a little on the low side, but if you don't overfeed or overstock your tank, you'll be fine. The LR in your tank will be the only thing reducing nitrates since your sand bed isn't deep enough to create an undisturbed anaerobic (oxygen free) area.

Most people with reef tanks only use LR/substrate, and protein skimmers for filtration and opt out of using mechanical power filters, cartridge filters, bioballs, etc... since they can get plugged up with detritus (waste) over time and cause nitrates to rise as the waste breaks down in the filter.

BTW - We all started out not knowing anything about reef keeping. At least these days, there are good on-line forums to ask questions and learn from. Before Al Gore invented the internet, it was much tougher to get information about products and methods for keeping reef tanks so everyone had to rely on trial and error and reading outdated books.

BTW#2 - There are a million different ways of doing things in this hobby and no one right way so try to learn from what you read and determine what methods will work the best for you. We, as a group, try to express what we have found to be a good method for our own tanks and watching what has worked for other people.

I'm going to be sending you a PM very soon about corals, so be looking for it.