Right Amount of Live Sand?

I have a 2 1/2 week old 46 Gal. tank with 40 lbs of live sand. I was wondering if 40 lbs is enough. I have measured the sand bed from the bottom up, it measures only 2 inches! and so before buying any more sand I thought I'd ask you guys first. So, can I add more after 2 1/2 weeks? Please let me know. Thanks. Also, these spots have developed on the sand: what are they?

I forgot to mention the type of sand I have, it's Aragonite Ocean Direct Caribbean Live Sand.

A final question, I was planning on adding this:

Walt Smith's Fiji Gold Coral and Live Rock Supplement
* 100% natural calcium supplement for reef aquariums
* Made from seawater and coral reef substrate
* Contains calcium, magnesium, and other major trace minerals

to promote coralline algae grow...Will this help in any way? keeping in mind that my tank's only 2 1/2 weeks old. Thanks again guys. Peace.

 

There has been many debates on the sand depth issue, do a search on sand beds.

 

I use Walt Smith's products and I like them. I would use it...
Your sand bed depth can be beneficial or detrimental the deeper the sand bed. Bacteria and the denitrification and gas exchange process will be better achieved with a deeper sand base. The ability to house more organisms and provide more food for benthic organisms also exists.
The major drawback is that IF you have a power failure, your dissolved oxygen level within your tank will diminish drastically causing suffocation of your livestock! Also, warmer temperatures will inhibit the growth and population of many organisms residing within the benthic area of your tank as well!
Some food for thought!
As geek stated do some research to educate yourself further!

 

Hey again reefer...so, is it safe to add more sand now? and also, did you check those spots in the pictures? Please let me know that they are and about the adding of the sand. I will do some more research. But for now I need your opinion about adding more at this stage in the tanks life. Will I be disrupting anything? ...anyway. thanks again!

 

Unless you plan on siphoning out your sand bed once a month or something, I wouldnt go any deeper. Deep sand beds are only good for a few years. Then they become worthless in aquariums and could crash your whole system. It does not take the power to go out for it to destroy a tank. If deep sand beds were so great, if the power went out for a few days (assuming the temp. stayed within the limits) all this supposed good stuff in the DSB would maintian proper levels of o2 and other elements but as we all know, it doesn't.

as for the pics, that looks like diatoms.

 

Thanks geek! I truly appreciate your help. I will keep it the way it is then. Have you got any idea if the supplement I listed above would be a good addition to the tank during the cycling process?

 

Also, about the diatoms, I've been reading/still reading articles about them, but nobody really says whether they're a normal/natural occuring part of the cycling process, if they'll go away, any ideas?

 

You will always have diatoms. They are one of the first signs of cycling. Right now, you are just trying to grow bacteria, nothing else. I wouldn't bother supplementing right now, test your water, if your calicum is less then 400ppm, then add some, if not, don't.

You never pics of other peoples tanks with diatoms because they scrape it off before they take a pic of it. Once you have you're bacteria, they will compete with the diatoms for food. Lots of bacteria=very little diatoms.

If I remember correctly, first its diatoms, then hair algae, then its over. in the words of Mtt "go slow, let it grow", nothing good ever happens fast. The only thing that would really help you right now is possibly something like stability, made by seachem or some other product thats bacteria in a bottle. But again, if the bacteria doesn't have enough food,it will die off as well.

 

If you would like to add more sand at this point, feel free to do so. I have been using the DSB method for years, with positive effects since.
One thing to add, is that you will want to replenish some sand(aragonite) every year, as your live rock and sand will depreciate over time a it is broken down etc.
The brown is probably diatoms as Geek stated. As quickly as they come they are gone and are casued by excess silica in your water, I believe...
Good luck!