thesassyindian
Supporting Member
My tank is at 9.5dKH, and my new salt mix is 11.5dKH
Is it safe to do a 50% water change?
Is it safe to do a 50% water change?
Regarding those alkalinity ranges, it’s worth pointing out that natural reefs in the ocean are around 7 dKh, and that some of the more controlled systems out there recommend aiming for 7 or 8. There are lots of reports of people causing a ton of coral damage by pushing the dKH up into the 10+ range and having the slightest perturbation come along and cause a crash. You can find the 8-12 range referenced lots of places online, but I don’t agree with it, I think it’s somewhat outdated and risky advice. I keep mine around 8.5.You should probably be fine. I manually dose once a day to bring my tank up from 7.8-ish dkh to 9 dkh over the span of 5 minutes or so. (I would not necessarily recommend doing this, I have just been lazy about setting up my dosing pump and this has worked well for me for three months now.)
Popular wisdom holds to alter dkh by no more than 0.5 or 1 dkh/day (depending on your source), but Red Sea suggests no more than 1.4 dkh in a 24 hour period.
You're still towards the low end of the recommended range (8-12 dkh) so it should be fine. Any higher and I'd be a bit concerned, since Alkalinity acts like a buffer, and buffers aren't linear in their buffering capacity. They buffer real well... Until they suddenly don't, and pH/calcium/etc can go out of whack very quickly.
+ @max_nanoYeah just post this in your journal rather than making a new thread
Regarding those alkalinity ranges, it’s worth pointing out that natural reefs in the ocean are around 7 dKh, and that some of the more controlled systems out there recommend aiming for 7 or 8. There are lots of reports of people causing a ton of coral damage by pushing the dKH up into the 10+ range and having the slightest perturbation come along and cause a crash. You can find the 8-12 range referenced lots of places online, but I don’t agree with it, I think it’s somewhat outdated and risky advice. I keep mine around 8.5.