Kalk Drip Rate

intenseimage

New member
So im finally setting up my Kalk Drip ... have a RENA air pump hooked up to a milk jug with a line running to the tank. As the pump pressurizes the jug it pushes water up the tube and into to the tank. My pump is run via the ACIII and turns on when the lights go out and also will turn off should the pH go above 8.3

The kalk is dripped into into the return section and the pH probe is in the middle of the sump by the skimmer so it will have more than enough time to mix so the readings arent skewed.

The only thing Im trying to figure out is drip rate. How fast should this drip in?

Tank is a 75g with a 29g sump --- looking mainly to keep pH up/steady since my Cal/Alk demand is fairly low (loose approx 1 dKH every 2 days)
 

Randy Holmes-Farley

Reef Chemist
Premium Member
The idea is to spread the addition out over many hours. Whatever rate meets that for the amount you need to dose is appropriate. :)

FWIW, I would not shut off limewater additions unless the pH got above 8.55.
 

bertoni

Premium Member
8.5 generally isn't high enough to cause any problems. If your measuring equipment is a bit iffy, you might want to be a bit more conservative.
 

Randy Holmes-Farley

Reef Chemist
Premium Member
Many people with tanks using limewater run in the pH 8.4-8.5 range routinely. Mine was that was for years. IMO, pH 8.5 is better than is pH 7.9.
 

intenseimage

New member
I mixed up 1 tsp into a gallon of RODI last night and set it to turn on when the lights went out and drip at the rate of 1 drop/sec (roughly).

My pH at the time of the Kalk addition was 7.79. Overnight it dropped to a low of 7.78 and is currently at 7.82 (lights still arent on yet).

How long would you expect it to take to show an increase in pH? Im guessing after at least the first gallon is consumed?
 
Randy, if you calibrate your ph meter as often as you run tests on your other parameters, then it may have been months since you calibrated your meter. :lol:
 

Randy Holmes-Farley

Reef Chemist
Premium Member
How long would you expect it to take to show an increase in pH? Im guessing after at least the first gallon is consumed?

If you added 1.25% of the tank water volume as saturated limewater all at once, the pH will INSTANTLY jump by 0.6 pH units or so. After a day adding limewater, the pH has likely reached the pH it will continue at for future days. If the limewater is not enough to boost the pH, then more fresh air or more limewater are about the only options.

Randy, if you calibrate your ph meter as often as you run tests on your other parameters, then it may have been months since you calibrated your meter.

:lol:

I do calibrate it frequently enough to ensure that it hasn't drifted much. I've calibrated a lot this fall since my system now runs about pH 8.0 instead of 8.4, presumably due to our new storm windows. I did not expect such a large effect, so I've frequently recalibrated to be sure it was real. :D
 

Jason Donohoe

Premium Member
You also mentioned you added 1 tsp to 1 gallon. You would need aprox twice that amount to produce a fully saturated solution and maximize your Ca and alk benefits with the same volume. I would suspect (but I'm not certain) it would also change the effect on pH.
 

tmz

ReefKeeping Mag staff
Premium Member
I think higher saturation would definitely increase ph.
BTW I've never heard of anyone using an air pump pressure doser with limewater before. Is there any concern about the continuous infusion of air and CO2 in terms of loss of strength and precipitation. I know it holds it's strength in a still resevoir . Just seems this application might cause too much air exposoure.
 

intenseimage

New member
So ... dripped almost a full gallon (1 tsp / gallon mix) last night

pH hit 8.03 today, Alk remained steady at 9, Cal steady at 420


I will mix up another batch tonite and see what happens tomorrow.

As of right now its easier to mix up some Brightwell Alk8.3 (5 tsp in 1 cup RO) and dose that once a day for 2 days to maintain those levels
 

Randy Holmes-Farley

Reef Chemist
Premium Member
Watch the alkalinity. That has a much smaller pH boost and a larger alkalinity boost. It is not usually the best bet, especially since it not balanced by matched calcium additions.
 

intenseimage

New member
My alk drops approx 1 dKH a day ... with the Alk8.3 dosed as mentioned I kept my alk stable and gained a bump in pH ... my cal drops VERY slow and I dose cal as needed (which isnt often)
 

bertoni

Premium Member
Calcium should drop about 7 ppm per day with that alkalinity consumption rate, so that's a small change. Over the longer haul, people have gotten themselves into trouble by using unbalanced additives, but if the testing rate is kept up, the tank should be okay.
 
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