Kalkwasser
Recently I’ve been measuring my Alkalinity (using a couple salifert test kits) and seeing the measurements ranging between 6.5 and 6.7. I’ve slowly up’d the Kalk drip and increased the Sodium Hydroxide dosing. Yet, I’m still having a hard time pushing it up over 7.
I believe the coral uptake has increased since my calcium has also dropped in line with alk measurements (or it’s the Kalk, more later). And since I’m using a couple alk test kits I’m pretty confident that I’m not getting a test error. Also note that I test every two days at the same time during coffee.
I mixed up a new gallon of Sodium Hydroxide yesterday since my current jug will be running out soon. But this slow alkalinity climb (which I’m not complaining about, I rather the increase go very slowly) is not characteristic of this tank.
What can be causing this change?
- I need to calibrate the DOS pump. I haven’t done this in a year and it’s possible the head is off and is not adding the amount of NaOH I think I’m adding.
- I recently couldn’t find my unopened bag of BRS Pharma Kalk. But my pH prope in the Kalk Stirrer was showing that the Kalk concentrate was really low and needed to be replenished. I ordered a 5 gallon Avast Marine Kalk supply. But to carry me over I stopped by my LFS (Oceans Tropical) and picked up the Kalkwasser they had available — which was Seachem’s Reef Kalkwasser brand:
I just want to note a couple of things I noticed immediately: It took much more Kalk of this Seachem powder to get my pH probe to measure a pH of 12 than it did with the BRS Pharma Kalk. I would only add ⅓ cup of BRS Pharma Kalk to get to a reading of 12 pH where it took nearly ¾ of the Seachem brand. Not sure why. But I was a little surprised.
In any case, I’m still using this Seachem Kalk to use up the container — which lead me to another observation: the pH drops a lot faster and needs to be replenished so much sooner over the BRS Pharma Kalk. Where I would replenish the BRS Pharma once every week-and-a-half I need to replenish the Seachem Kalk every 4 days to maintain a pH level above 11.5.
I’m hoping when I switch to the Avast Marine Kalk that the quality is closer to the BRS Pharma Kalk.
Conclusion, I suspect the Seachem Kalk is playing a part in my slow alk climb.
