Dosing Kalk to Raise pH

[CastAway]

My pH is consistently 7.9 when I test. Not a problem, but perhaps not ideal. I'd like it to be higher, closer to common target values. Of all the means to raise it, I'm most curious about dosing kalk.

Could a kalk reservoir and a pH controller be used independent of my ATO to maintain my pH?

I average 2g per day in evaporative loss on 210 total gallons. I may be confused about running an independent kalk dosing system vs simply topping off with kalk.

Thanks in advance for your reply Randy.

 

[CastAway]

Maybe one question would be, how much of a saturated kalk solution would be required to make or maintain a .3-.4 shift in pH?

 

[GoVols]

Maybe one question would be, how much of a saturated kalk solution would be required to make or maintain a .3-.4 shift in pH?

I agree that your ph is not that bad.

Have you tried Randy's (PH - Bubble - Cup - Outdoor - Test) to see if you have trapped in CO2 in your home?

 

[saltyfilmfolks]

I agree that your ph is not that bad.

Have you tried Randy's (PH - Bubble - Cup - Outdoor - Test) to see if you have trapped in CO2 in your home?

Good call. I think he would have to have a co2 prob. With that many corals it should be co2 or rest error I would guess.

 

[GoVols]

Good call. I think he would have to have a co2 prob. With that many corals it should be co2 or rest error I would guess.

Salty,
I'm a window opening, junkie

 

[saltyfilmfolks]

Salty,
I'm a window opening, junkie

Lol. Big fan of leaky old houses here.

 

[MounteeFrag]

I made my own co2 scrubber. Cost me $ 9 every 5 weeks

 

[GoVols]

Lol. Big fan of leaky old houses here.

Never had ph issues until we downsized to a tightly built town-home.

Re-read Randy's ph article and it did the trick

 

[beaslbob]

first measure pH just before light out.

Second measure alk and add baking soda to get alk above 8 dkh.

Low pH is always a function of co2 when alk is at normal levels. Macro algaes will lower co2 and raise pH. Hence the measuring pH just before light out. Using macro algae (or other plant life) will make the tank a net consumer of co2 and producer of oxygen regardless of the ambient conditions. and that is a good healthy system regardless of the PH. but usually the pH rise is noted.

my .02

 

[CastAway]

In my own relative ignorance, and kind of echoing @beaslbob, I know I have a CO2 issue. My favorite seasons for reefing are spring and fall because I can open the windows, improve gas exchange, and raise pH.

I need to do this test it sounds like. I get the impression there are one of two paths, depending on the outcome. I already know I can shift my pH with improved gas exchange however. I just want a year round alternative solution. The residual CO2 from my ca reactor drives my pH down and contributes to the issue.

 

[Ty Hamatake]

I'm pretty sure I saw a couple online calculators that @Randy Holmes-Farley posted a couple weeks ago that could help you dial in you kalk dosing. You could always just do trial and error, start low and slowly increase the amount dosed until you find the sweet spot.

I know you're asking specifically about dosing kalk, but have you considered a CO2 scrubber?

 

[Randy Holmes-Farley Verified Community Expert]

Adding 1.25% of the tank volume with saturated limewater will boost the pH instantly by about 0.7 pH units, but the effect rapidly wanes as the system pulls in more CO2 from the air.

There's no way to determine in advance how much using limewater will boost pH overall, but be certain alkalinity does not get higher than you want.

 

[cilyjr]

I use a kalk reservoir that is independent of my top off water. A peristaltic pump doses kalk a few mins every hour through out the day. Many of ca reactors do as well.

For me it was a dose slowly and adjust (both the kalk and ca reactor) to get to where I want.

I don't know about using a ph controller on a kalk bucket but you could use something like an apex to help. You would write a prgm with your dosing times then add a statement like ( if ph> 8.3 then off)

For me, without kalk my ph will dip to about 7.4 to 7.9 with kalk I'm at 7.8 to 8.2 for my diurnal swing.
I should also mention my skimmer pulls external air. I also have an independent air pump out side to push air in AND I run chaetomorpha in a bucket with opposite lighting. But it's really only the kalk that helps.

 

[beaslbob]

In my own relative ignorance, and kind of echoing @beaslbob, I know I have a CO2 issue. My favorite seasons for reefing are spring and fall because I can open the windows, improve gas exchange, and raise pH.

I need to do this test it sounds like. I get the impression there are one of two paths, depending on the outcome. I already know I can shift my pH with improved gas exchange however. I just want a year round alternative solution. The residual CO2 from my ca reactor drives my pH down and contributes to the issue.

Then add macro algae to consume the co2.

 

[BluewaterLa]

Macro algae is a good consumer of Co2 especially when it is provided with a strong light source with proper spectrum.
BRS has a couple good videos on this very subject. Lighting can make a huge difference in how efficient macro like cheato is or is not when it comes down to PH increases and nutrient reduction.

 

[CastAway]

Very helpful @cilyjr. Thanks

I have a 25g refugium packed with macro (caulerpa brachypus) lit 24/7 with a four bulb T5HO fixture.

I don't draw in any outside air for my skimmer, but seasonally I do open the windows. I micro bubble intermittently as well.

I've looked into CO2 scrubber media, but don't think I can justify the cost over time.

Perhaps an alternative is a new dual chambered ca reactor, and addressing the residual CO2 issue that way if I could mitigate the effect of the ca reactor, I'd guess my pH would naturally be where it ought to be.

I don't want to risk high all by dosing kalk.

 

[cilyjr]

I have a 2nd chamber on my calcium reactor as well.

If you started using kalk with a calcium reactor, you'd just slow the ca reactor drip to compensate for the new source of alk.

 

[cilyjr]

The ph difference between the reactor with the 2nd chamber is adds about .3 ph I'm my setup

 

[OceanDiver]

I use a kalk reservoir that is independent of my top off water. A peristaltic pump doses kalk a few mins every hour through out the day. Many of ca reactors do as well.

For me it was a dose slowly and adjust (both the kalk and ca reactor) to get to where I want.

I don't know about using a ph controller on a kalk bucket but you could use something like an apex to help. You would write a prgm with your dosing times then add a statement like ( if ph> 8.3 then off)

For me, without kalk my ph will dip to about 7.4 to 7.9 with kalk I'm at 7.8 to 8.2 for my diurnal swing.
I should also mention my skimmer pulls external air. I also have an independent air pump out side to push air in AND I run chaetomorpha in a bucket with opposite lighting. But it's really only the kalk that helps.

are you still having success with this method ? I am planning on doing the same.

CO2 scrubber and outside air to skimmer already setup which stabilized my ph between 7.94 and 7.88 depending on the time of day. Before that I would get into the sub 7.6 area.

I have a DOS coming and a reservior for kalk. Planning on doing 500ml throughout the day which is below my ATO requirements and I will reduce my addition of 2 part as needed to maintain levels

 

[boacvh]

Newbie here. Following this thread. I have been dripping kalk from a k1 stirrer in addition to my 2 part. I saw no improvement in my PH range. So I added a co2 scrubber as well. Still haven't seen improvement in the range. I also run chaeto in a reefugium (but it is small).
My usual range is 7.8 - 7.9 so not very concerned, but would like it a little higher if I can so definitely following