What else to dose?

[spikehs]

I have a 4 part doser that I am going to hook up to my 12g nano (when i finally get it setup!). I am planning on doing mainly (if not 100%) sps in there. This is what/how I am dosing so far...

1 - Calcium
2 - Alk
3 - Mag
4 - ??

I have an auto top-off system that I am using for kalk, so I should have more than enough calcium for the tank.... not sure if there is really anything else worth dosing? Thanks!