Well, here are some ideas to ponder. TM's Bio-Ca+ contains carbonates in it already, which means it'll raise the KH as it raises the Ca+. This isn't a big problem unless the two are on opposite ends of the spectrum (i.e. Ca+ is low but KH is high). Right now, you're in good shape to use this since both your Ca+ and KH are both low. But, if you ever need to raise Ca+ independently, I'd use a Calcium Chloride product. Seachem's Reef Advantage Calcium is a readily available, easy choice. I'm sure you probably already know this stuff, but it's better to have too much information than not enough.
If you feel comfortable, I'd definitely increase your dose. I dosed about the same as your current dosing in my 30g. So, it wouldn't be crazy for you to go higher. I might increase all of the dosing by 50% and then test after an hour or so. It should mix before an hour, but it's always good to wait a little.
Kalkwasser's great, but honestly, before you go on your trip, I'd try to lock in a very solid dosing regiment that keeps your levels a bit higher. If you do this and can trust someone to dose accordingly while you're away, then I think you can feel more confident about leaving the tank for a bit. Just get them to dose and top off with water (already buffered in buckets), and everything'll be fine. There are quite a few things that could go wrong with aquadosers (what if it's clogged, not a big deal unless no one's paying attention). I hope I'm not being a 'know-it-all' (cause I don't, obviously!
) or that I'm not stepping on your toes. I do feel pretty confident when it comes to keeping my levels locked in place; it's just the parasites that I HAVE to dodge. :lmao: