Malic acid = tart cider?

I just finished up my first batch of cider, and while I'm a big fan (suprisingly drinkable!) I was hoping for a bit more tartness. I used the typical ingredients (juice, nutrients, yeast, concentrate to carb/backsweeten) with the hope that carbing it up would brighten it up a bit.

I'm still waiting for it to carb up to the right level, but I don't think the final result is what I was looking for.

Anyways, I know that adding malic acid is supposed to give it a tartness, but is also used to adjust acidity (this is a little deeper into the brewing process than I am familiar with) and can cause malo-lactic fermentation.

I saw UpstateMike's KISS recipe and figured that the malic acid added was the difference, but I wanted to make sure.

Am I on the right track?

Also, can you add into the secondary?

Yep, malic acid will increase the tartness of cider. Carbonation will as well due to the carbonic acid created. Malic can be added at any point, pre, during, and after fermentation as well as in the serving glass if you really messed up the balance.

Adding malic will not cause a malo-lactic fermentation to occur, for that you need a MLF culture.

I like to add the malic acid in the bottling bucket, so you can judge by taste. I find that 1 to 1 1/2 teaspoons per gallon seems to do the trick.