I'm looking to start dosing Kalk. I was going to use the ATO like I did in the previous incarnation of my tank, but that seems to be out of favor now, and people recommend dosing pumps, which makes sense. The DOS is just too expensive right now, so I was looking at the BRS 50 ml doser, and I'm pretty sure I know how I would set that up with Apex. But then I started looking at possible future applications, and there is this 4-head Simplicity doser for a bit under 2x the price of the BRS single. I'm actually not sure if it can supply enough for Kalk but at least in theory, is it possible to control a multi-head dosing pump with Apex, other than DOS? If you're just using the outlet, it seems like it would be all or nothing. For instance, say I'm dosing 2-part, NOPOx and Kalk, and my pH hits an upper boundary, I would want to turn off Kalk, but not NOPOx. Is that possible? I am guessing it's not...