No PH bump from Kalkwasser

Panicked Reefer · Jul 28, 2022

I have recently started to dose kalkwasser. My depletion rate is pretty low. My tank only uses approximately .3 dkh a day. I have started to ween off of 2 part onto the kalk. I am up to 37ml/hr of kalk for a total of 890 ml/24hr. My standard deviation in ph prior to adding kalk seems to be 7.9 to 8.1. I had one test return a 8.4 but that appears to be an inaccuracy. I am approximately 24hrs into dosing kalk and there is no increase in ph. Is this common, am I doing something wrong, is the amount I require not enough to boost the ph?

haitian_reefer · Jul 28, 2022

Are you sure your reading is accurate?

Panicked Reefer · Jul 28, 2022

haitian_reefer said:
Are you sure your reading is accurate?

As sure as I can be with a Hanna checker. I'm sure it's not lab accurate but my procedures are as uniform as I possibly can make it. I'm not sure of the exact number but I am fairly certain there's not been an increase.

mdb_talon · Jul 28, 2022

If you are reducing 2-part dosing and increasing Kalk dosing by same amount(in terms of alk added) I don't really think you would see much of a difference in PH depending on the 2-part you are using as I believe they both could have same impact on PH. Kalk usually spreads the impact out a bit better because you have to dose a lot more to add the same amount of alk but over the course of 24hr I don't think you would usually see a difference.

Panicked Reefer · Jul 28, 2022

Gotcha, that makes sense. I was under the impression that kalk was had a much greater impact on ph than 2 part does. I've added a fresh air like to my skimmer this week and that pulled it up from 7.7 for my low to 7.9 as the low now but hasn't really improved the peak. I'm still only topping out at about 8.1 I was hoping to squeeze a lil bit more ph out with kalk but it appears that's not going to make the impact I anticipated. I wasn't sure if I have done something wrong or the amount I'm adding was insufficient. I had not considered I could be observing a similar sized bump from my 2 part already.

Randy Holmes-Farley · Jul 29, 2022

0.3 dKH per day is not enough to give much pH boost.

Even if you added it all at once, the pH boost is only about 0.13 pH units, and when added slowly, will hardly show up.

When alk demand is that low, other means may be needed.

Panicked Reefer · Jul 29, 2022

Randy Holmes-Farley said:
0.3 dKH per day is not enough to give much pH boost.

Even if you added it all at once, the pH boost is only about 0.13 pH units, and when added slowly, will hardly show up.

When alk demand is that low, other means may be needed.

What are the benefits of using another means at this low dose? I ask because the ph was only one of the parts in my decision to go with kalkwasser. The others were cost, the reports of its impact on phosphates, and for some reason my calcium has always been consumed a bit more than my alk and end up having to dose the tank with a small amount of cal once a week. I'm curious to see if the benefits of 2 part out weigh kalk at these levels. Thanks in advance for the knowledge!

Randy Holmes-Farley · Jul 29, 2022

Panicked Reefer said:
What are the benefits of using another means at this low dose? I ask because the ph was only one of the parts in my decision to go with kalkwasser. The others were cost, the reports of its impact on phosphates, and for some reason my calcium has always been consumed a bit more than my alk and end up having to dose the tank with a small amount of cal once a week. I'm curious to see if the benefits of 2 part out weigh kalk at these levels. Thanks in advance for the knowledge!

By “other means” I meant other than dosing. Like fresh air to the room or a CO2 scrubber.

Panicked Reefer · Jul 29, 2022

Randy Holmes-Farley said:
By “other means” I meant other than dosing. Like fresh air to the room or a CO2 scrubber.

I gotcha, I thought you were talking about 2 part vs kalk. I can't really afford a c02 scrubber or media at the moment so I ran a line to out side. I saw an improvement from 7.7 low and 7.9 high to now a 7.9 low and about 8.1 high.

Randy Holmes-Farley · Jul 29, 2022

Panicked Reefer said:
I saw an improvement from 7.7 low and 7.9 high to now a 7.9 low and about 8.1 high.

That's certainly an acceptable range.

Gatorpa · Aug 13, 2022

Panicked Reefer said:
I gotcha, I thought you were talking about 2 part vs kalk. I can't really afford a c02 scrubber or media at the moment so I ran a line to out side. I saw an improvement from 7.7 low and 7.9 high to now a 7.9 low and about 8.1 high.

Most people would love a 0.2 pH bump from a fresh air infusion to a skimmer.