Kalk

[Alwmh4]

does kalk lose ability to raise ph over time? I add my regular 2 part alk before ph meter and you'll see it jump way up momentarily. With kalk it might bump up a couple hundredths for a second but nothing like the 2 part

 

[Randy Holmes-Farley Verified Community Expert]

I'm not sure what you mean.

Almost anything you do to impact the pH of seawater is temporary. Aeration brings it back in line with the alk and the CO2 level, which is what determines pH.

If you mean does it go bad, yes, limewater exposed to air reacts with the CO2 in it and can be degraded by making calcium carbonate.

Limewater has a much bigger impact on pH than a two part, in terms of pH raised per unit of alk added, but it is necessarily much more dilute and takes more fluid to raise pH and alkalinity.

 

[Alwmh4]

Ok so volume to ph ratio isn't the same across kalk and 2part correct. 10cc of kalk is much weaker, in regards to ph, by volume than 10cc of 2 part

My label for kalk offered no input to try to figure out anything so I've been guessing. Adding 50cc of kalk per day for last week and not change in ph. Tank is bout 170 ga total water volume


I have my kalk in a glass jar w quark stopper in top and hose running through stopper. It's not air tight obviously as a vacuum would be created.

 

[Waterjockey]

Ok so volume to ph ratio isn't the same across kalk and 2part correct. 10cc of kalk is much weaker, in regards to ph, by volume than 10cc of 2 part

My label for kalk offered no input to try to figure out anything so I've been guessing. Adding 50cc of kalk per day for last week and not change in ph. Tank is bout 170 ga total water volume


I have my kalk in a glass jar w quark stopper in top and hose running through stopper. It's not air tight obviously as a vacuum would be created.

50 cc? Far too little to make any difference in a tank that size. For example, I have my kalk mixed 50% saturation in a 25 gallon trash can and use it as my top off water...a little under a half gallon per day (about 1,500 ml).....in a 40 gallon total system volume mixed reef.

 

[Randy Holmes-Farley Verified Community Expert]

1.25% of the tank water volume added in saturated limewater will boost alk by about 1.4 dKH, so quite a lot is needed to be dosed slowly.

 

[Alwmh4]

50 cc? Far too little to make any difference in a tank that size. For example, I have my kalk mixed 50% saturation in a 25 gallon trash can and use it as my top off water...a little under a half gallon per day (about 1,500 ml).....in a 40 gallon total system volume mixed reef.

That's great to know. I was really scared of overdoing it. I figured though that it wasn't enough. I mix mine at full saturation. Precision is brand.

 

[Alwmh4]

1.25% of the tank water volume added in saturated limewater will boost alk by about 1.4 dKH, so quite a lot is needed to be dosed slowly.

This is what I needed! So what is considered safe increase in dkh per day?

 

[FlyinBryan]

I feared Kalk at first for this very reason, spiking ph. However, once I overcame that and realized it's really safe and very effective for maintaining overall good balance in the tank. Great sps and lps growth even under metal LEDs!! I dose it through my ato and have for years!

 

[cmcoker]

This is what I needed! So what is considered safe increase in dkh per day?

Recommend you read this article by Randy Holmes-Farley. I have read it many times and reference it first when looking for kalk info. http://www.reefkeeping.com/issues/2005-01/rhf/

I wouldn't use lime to raise dkh, I would use 2 part to correct to the desired level and then use limewater to maintain the level.

 

[Randy Holmes-Farley Verified Community Expert]

This is what I needed! So what is considered safe increase in dkh per day?

Safe is whatever your tank needs, but pH spikes if you add too much too fast.