Any details about how you're adding your Kalk? You mentioned Hydros, so I assume you're dosing and not going the ATO route. Are you using a slurry or a mixed set amount per time period? How often are you rinsing/cleaning your reservoir? Do you only dose at night, and have a max pH to stop? What about evaporation, did you measure your evap and alk drop in a day to calculate how much kalk to add? Ahh so many variables!
I ended up buying the kalk you linked. Thank you! Everything should arrive Monday next week!
I dose fully saturated kalkwasser out of a 44g brute. Any calcium hydroxide that doesn't dissolve, settles on the bottom. My feed line is above the sediment to avoid dosing any slurry. I have only cleaned my reservoir once so far. Probably something I'll do every couple months.
I dose all day since I have opposite light cycle tanks on the same system. I'm using a
peristatlic pump to dose based on pH. On at 8.3 and off at 8.34(contolled by
hydros). The peristaltic is set to about 15ml/hour. I'm dosing roughly 3g/day. This will give you an idea of how often it kicks on and off.
No calculations. I'm just letting pH decide how much to dose. I am no longer shooting for a specific alkalinity. Although I have found alk is relatively stable day to day with this method. It's just been higher than most people would comfortably run. I started at 7.4 and climbed quickly over a couple weeks maintaining 8.3pH. At peak I was nearly 13dkh, then mid 11's for a while, most recent test was just over 10. There has been a gradual and slow drop in alkalinity over the last couple months as consumption increases. Wouldn't be surprised if I'm in the 9s now. No big swings that I've seen, but I don't test alk often, so could be wrong.
You could set your K1 up to your ATO pump and dose your kalkwasser that way. I know a local guy who's been doing this for years with no issues. You could also get a separate dosing pump or peristaltic and feed your K1 from say a 5g bucket of RO water. I think this might be the safer route to go if you want to use it alongside AFR. You will have more control to maintain whatever alkalinity you're aiming for.
Can't help you with calculating exactly how much to reduce AFR and replace with kalkwasser. To be honest I found balancing the two to be a PITA. But I'm also kinda lazy and stupid. :) There's a lot of people successfully using both of these in sync with beautiful tanks.