Ammonia 0 with Nitrites spiking means that your tank is cycling. Expect Nitrates to raise even higher. At three weeks I figure you are in the right direction.
IMHO (despite being unsolicited) using strip
test kit is a major risk even in
FW. Major disaster waiting to happen in SW.
Why are you using only 1.5 lbs of live rock? Do you plan to add inert rock that you expect to seed from your fragment of live rock?
I don't know if using crushed coral as substrate is a good idea. Definitely not safe for soft belly or sand sifter fish. Being a 10gal tank, using this type of substrate restrict your stocking options (e.g. not safe for the small blennies, gobies...).
Are you going to use live rock rubbles inside the
HOB or are you using the standard filter media? Be careful so you don't end up with a filter that turns out to be a
nitrate factory.
Have you searched for information on the utility of bio-wheels in SW? (I ask because I have no clue)
Some values suggest that your measurements are indeed wrong (not your fault, it's the strip test error). In what I consider a fairly honest review of Salt Mixes, using Oceanic at 35 parts per thousand (ppt) or Specific Gravity of 1.0264 at temperature of 25C, gives around 8.5dKH. KH at 180meq/L, if accurate, means 10
DKH which is OK per se but your Specific Gravity is likely higher than 1.026. To read that review please click here:
http://www.reefcentral.com/forums/sh....php?t=1714505
Your pH reading is way low for SW but I wonder what is the real value of your tank. pH strip tests are unreliable, no matter who manufactures them. Since pH reagents used in SW are different form those used in FW make sure you have the right kit.
As for detecting Nitrates and Nitrites I have found strip tests to be at their best.
I don't mean to discourage you but to share with you some of the ideas that I consider you should be looking into now when you could afford to reconsider your set-up, that is before adding expensive marine life specimens to your Nano tank. I'm a newby in SW as well.
Pepetj
Santo Domingo