The buffer should work to bring up alkalinity into the 2.5-4.0 meq/L range (most reefers aim for near the top of that range because alk is used up by stony corals and some other reef animals). If that kit is reading dKH, then your alk is SUPER low. When you dose it, just make sure you are dosing the appropriate amount of it. I find the reef chemistry calculator to be helpful in this.
http://home.comcast.net/~jdieck1/chem_calc3.html
With that in mind, I'm wondering what test kit you are using. If it is reading a range (as it seems it is) you might want to think about getting a better kit (if not now, at least the next time around). The three test kits that are worth really investing the majority of your test kit budget on are calcium, alkalinity, and magnesium since they are the three things you will need to test for regularly (especially if you add more stony corals).
To raise salinity I honestly just slowly add salt directly to the aquarium in a high flow area and only a little bit at a time (so you don't overshoot your mark). With a nano it might be a good idea to make a high salinity solution so that the salt is already dissolved. Honestly 1.022 isn't that bad at all, but it could be contributing slightly to the low alk problem, so you should fix it. Don't add salt to your topoff unless you can easily get it back out and will be able to monitor when you reach your set point.
Now, fixing the underlying alk problem.
http://www.advancedaquarist.com/issues/nov2002/chem.htm
That article quickly mentions magnesium, which you should also read up on.
Since it sounds like your tank should be pretty low demand as far as calcium and alkalinity (and I'll assume you are doing relatively regular water changes), your tank water should not have too much of a chance to change a whole lot from the water you are doing your water changes with (if this was a dirty water problem, your alk might be low, but I would also expect your pH to be running low and 8.2 is pretty much right where you want to be). So, my guess on the culprit (again assuming you are doing regular water changes) is that your salt mix is low in alkalinity to begin with.
Oceanic salt runs relatively high on Calcium and low on alkalinity, so my shot in the dark guess is that you are using Oceanic salt or getting your water from the Aquatic Critter (I am fairly sure they use Oceanic salt). If that is the case, plan to adjust the alkalinity each time you mix up water. If that isn't the case, you should at least verify the levels of your mix-up water so you know if it is actually the tank that is using up the alk. If you're mixing your own water, you might try using a mix of instant ocean and oceanic (50/50), which should give you a salt mix that mixes up much closer to natural sea water.
