A promised update 3 months later:
So the topic of slamming kalkwasser into the system to stabilize and raise pH has been talked a lot about lately in this thread and elsewhere and after employing such a strategy for the past 6 months I feel the need to post some updates!
First of all -- does the strategy work??? Yes it certainly does! Things seem to respond well to elevated levels of alk and calcium as we all know and increased pH leads to fast growth.
HOWEVER -- there is such a thing as "too much". Talk about people running 8.5-8.7 pH is crazy. In my experience its not even very good for the aquarium overall. Let me say that I do not mean it will hurt the livestock, its just that at such a high level of super saturation precipitation does become a major issue.
Precipitation can have deleterious effects on coral health. Mainly a build up of heavy "debris" that arnt so easily taken away by flow makers. These debris build up on frag plugs, around the base of the corals or in some cases directly on top. The debris trap additional organics and detritus and overall this will hurt the health and perterb growth in my experience.
So, we decided at this point that the saturation level of the water (9dkh 450 calcium 8.4 pH) was good but not great because it was simply too high).
We began a strategy to back off the Kalkwasser a bit and bring the Calcium and Alk down (aiming for 8.4 dkh 410 calcium 8.2 ph). This involved getting a Calcium Reactor in the equation (we have had the calcium reactor for our 1200 gal acropora system since we began but it wasnt being used much due to the pH drawbacks).
It took a few weeks to ease the numbers down. The calcium reactor even running at very low (40 liters per day out of a possible 350L) certainly put a dent in the pH and hurt a little of our stability.
Now our pH swings a bit more than 0.1 (more like 0.15 now) so our daily is looking like 8.2 min 8.35 max
Our calcium has come down to around 410 and alk dkh is fluctuating around 8.5 min to 9 max.
It seems now that the system is happier than ever. Corals are looking very well, growth is nice and most importantly the precipitation debris issue has been resolved!
So i guess I am finding for our tanks that sometimes less is more and the people who are saying "just pump kalk who cares about the numbers" are frankly off base IMO. It is a crude strategy and it does work to some extent (for example if you cant keep any corals alive then it might be a place for you start) but its not ideal.
Dialing in the numbers to hold a just "slightly elevated" dkh/ca and a natural pH seems to be the best results overall.
A lot of science out there does suggest more dkh and more ca is "good" but i dont know that they have really examined when high is too high or at what point the negatives outweigh the positives. Randy has certainly given us a lot of great info over the years about super saturation and precipitation and I advise everyone to read and re read those articles and remember 8 points of calcium is more than you think it is!
Our averages for this week are 8.19 low and 8.36 high around 8.25 average pH. Our alk is 8.5-9 and calcium lower at 410 -- so far this has been our best result yet. (Even tho we had more stable pH at a higher number previously).
Our biggest improvement overall came from raising our tank temps to 82 degrees rather then all this other stuff. We used to run it at 78 which sometimes was more like 76. I am a firm believer in the increased temps and its the easiest change we made that had the most positive results.
There is also a scientific study I read recently which suggests (but does not prove) that increased temperature helps to relieve stresses related to pH swings. Average temp in study was 82min 84high and this was the natural temps of the water where the acropora was collected.
There could be other factors at play which would halt precipitation such as increased nutrients, increased magnesium or other unknowns so each system may be pretty unique in this regard but you'll know the problem when you see it.
Independently, I’ve been doing the same thing. Even the temperature!
I am dosing saturated kalkwasser via Neptune DOS. 2000 mL for a 24 hour period, set to turn off if pH is greater than 8.25. It usually starts dosing at 8 PM and turns off at 8 AM. My lights turn on 6:30 AM slowly ramp up ramp down turn off at 7 PM. This results in the lights influencing the pH and usually only 1500 to 2000 mL of saturated kalkwasser is dosed to my 50 gallon system water.
pH- My high and low depending on my CO2 in my home is usually 8.2 and runs up to 8.37 depending how much micro algae I have on the glass, which i find drives pH. pH is driven down by atmospheric CO2. At certain points when my house hold CO2 on is above 700 ppm, the kalkwasser dosage I use cannot overcome the effect on pH. I have skimmer pulling air from outside. Still my pH can drop on these high CO2 days to 8.15.
Alkalinity and calcium — I noticed my alkalinity jumped from average 8.3 to average 10.2 dKH. Now that it’s stabilized at 10.2 (measured at 3 PM everyday) I decided to measure at 9 AM, 1 hour later after the kalkwasser is no longer dosing, it is at 10.6. So there is at least .4 dKH swing daily from morning to afternoon. I find my Calcium runs very high 500 ppmwhich is the only thing I am dissatisfied with this method.
Temperature— I too am running my temperature higher, not for increased metabolism for higher growth, to acclimate the corals to the hurricane season.
I post my reasoning here . My temperature has slowly increased from 79 in May to 83.6 today.
Growth and color — definitely a bit faster. I’ve taken progress pics and it certainly has not slowed down.
I don’t have any trouble with color.
My thoughts-
It’s definitely cheap way going about caring for a tank. I do have to replace the 5 gallons of kalkwasser every Sunday. The main issue is volume wise CaCl and NaCO3 2 part solutions are more efficient gram per gram and volume for liquid. It’s nice that you only need one dosing head. It’s not easy to dose either or calcium and alkalinity independently. It doesn’t address trace elements like a Balling program can. I am dosing trace elements independently via a small addition daily where as balling can do those automatically. I am not sure if I will move to a balling program, but I would never start a tank without kalkwasser. It’s just so economical and easy.
