Kalk for pH

[paradizecityz]

I have low pH, struggling to even get to 7.7 and I want to try Kalk. Is it ok to use Kalk just for pH? Currently only dosing a little bit of Tropic Marin All for Reef so I know Kalk will raise cal and alk and I will dial back the AFR.

I was thinking of getting like a 10L container, mixing RO water and stirring up the kalk and then using a dosing pump to dose a few ml per hour, throughout the day. Is that Ok?

 

[PeterC99]

CO2 Scrubber would be more effective at raising pH and some will say that it’s easier than dosing Kalk.

 

[paradizecityz]

CO2 Scrubber would be more effective at raising pH and some will say that it’s easier than dosing Kalk.

I don't want to deal with constantly buying media for the co2 scrubber

 

[Randy Holmes-Farley Verified Community Expert]

A few mL is not useful.

You need to dose quite a bit of limewater (kalkwasser) to be useful for pH.

Something like 1% of the tank volume daily.

 

[Pistondog]

Adding kalk will also increase alkalinity unless your tank is consuming it.

 

[Pistondog]

Or run a skimmer line outside, if feasible.

 

[paradizecityz]

A few mL is not useful.

You need to dose quite a bit of limewater (kalkwasser) to be useful for pH.

Something like 1% of the tank volume daily.

Woah, 120 gallon tank so I would have to add 1.2 gallons a day? Glad I asked before buying!

Adding kalk will also increase alkalinity unless your tank is consuming it.

Or run a skimmer line outside, if feasible.

Understand the alk part and willing to monitor and adjust my AFR dosing.

Really don’t want to drill a hole through the wall lol

 

[ScottB]

I run a kalkstirrer with an APEX DOS to manage pH. It takes some dialing but I am happy with the range I am able to keep. Right now, I am dosing 3.6 liters per day into roughly 250G.

 

[Pntbll687]

Ok, to effectively use Kalk you need to dose a good amount. Like @Randy Holmes-Farley said above 1% of tank volume daily is a good place to start.

That said you also need to know the daily alkalinity consumption of the tank. Once you know that
go here

Reef Chemistry Calculator

Fill in the appropriate info. Let's say your alkalinity dropped .5dkh in one day, and you want to keep it at 8dkh. Put in 7.5 as current alk, and 8.0 as desired alk
Select saturated limewater as your additive

The resulting dose is what you need to dose in 24hrs to keep alk steady. DO NOT DOSE THIS ALL AT ONCE. Spreading it out over as many doses as possible through the day would be ideal. Personally, I use kalk on my 180g tank and dose 100ml every hour, simply because my dosing pump only allows 24 doses in one day.

Note - I would start at 75% of the recommended dose, and work up to the total dose, test every couple of days. This is simply to not overdose if your measurements of tank volume were off.

 

[PeterC99]

I don't want to deal with constantly buying media for the co2 scrubber

I recirculate CO2 scrubber air through top of skimmer. CO2 media lasts for months.

 

[paradizecityz]

I run a kalkstirrer with an APEX DOS to manage pH. It takes some dialing but I am happy with the range I am able to keep. Right now, I am dosing 3.6 liters per day into roughly 250G.

Ok, to effectively use Kalk you need to dose a good amount. Like @Randy Holmes-Farley said above 1% of tank volume daily is a good place to start.

That said you also need to know the daily alkalinity consumption of the tank. Once you know that
go here

Reef Chemistry Calculator

Fill in the appropriate info. Let's say your alkalinity dropped .5dkh in one day, and you want to keep it at 8dkh. Put in 7.5 as current alk, and 8.0 as desired alk
Select saturated limewater as your additive

The resulting dose is what you need to dose in 24hrs to keep alk steady. DO NOT DOSE THIS ALL AT ONCE. Spreading it out over as many doses as possible through the day would be ideal. Personally, I use kalk on my 180g tank and dose 100ml every hour, simply because my dosing pump only allows 24 doses in one day.

Note - I would start at 75% of the recommended dose, and work up to the total dose, test every couple of days. This is simply to not overdose if your measurements of tank volume were off.

I recirculate CO2 scrubber air through top of skimmer. CO2 media lasts for months.

Thank you guys for the detailed information. I will do further research on this topic

 

[BiggestE22]

I have low pH, struggling to even get to 7.7 and I want to try Kalk. Is it ok to use Kalk just for pH? Currently only dosing a little bit of Tropic Marin All for Reef so I know Kalk will raise cal and alk and I will dial back the AFR.

I was thinking of getting like a 10L container, mixing RO water and stirring up the kalk and then using a dosing pump to dose a few ml per hour, throughout the day. Is that Ok?

Kalk wont raise PH much. You need a CO2 scrubber. I use Kalkwasser in my top off reservoir and dose it. Even doing that only keeps my PH at 7.8. So kalk is not the answer to good PH levels.

 

[ScottB]

Kalk wont raise PH much. You need a CO2 scrubber. I use Kalkwasser in my top off reservoir and dose it. Even doing that only keeps my PH at 7.8. So kalk is not the answer to good PH levels.

My experience is the exact opposite. With a scrubber, I never got more than about .05 or so benefit. Plus, you cannot really dial in more/less very easily.

With saturated kalk, I could dose to deadly levels of pH with ease. In fact when we are away and the house is empty, I have to dial back.

My "normal" rate is 3,600 ml per 24 hours. My APEX DOS pushes RODI into a larger kalk stirrer, which then gravity feeds to the sump. My program doses only 700ml during the light cycle and 2,900 during lights out. Works like a charm.

As an added benefit, it reduces my two-part dosing by half, to about 240ml per day.

 

[arking_mark]

I contend that any well aerated tank that doesn't use a Calcium Carbonate reactor really can't have a pH less than 7.8. Chances are your pH meter is off.

If you pH is less than 7.8, your pH meter is probably wrong

Post in thread 'Aquarium pH Distilled' https://www.reef2reef.com/threads/aquarium-ph-distilled.853474/post-9330359

www.reef2reef.com

To raise pH you need to lower the effective CO2 levels in your tank.

• Keeping air around your tank/skimmer moving and well exchanged with appropriate CO2 level air (open windows, air exchange systems, outdoor air connected skimmers, CO2 Scrubber connected skimmers, etc…)
• Increase photosynthetic organisms in the tank such as macroalgae (Refugium with macroalgae running on a reverse lighting schedule will provide a boost at night to reduce common day/night swings)
• High-pH dosing such as Kalkwasser drip

If you're interested in diving deeper into pH...

Aquarium pH Distilled

I just wanted to share my understanding of reef pH which is mostly based on: Low pH: Causes and Cures by Randy Holmes-Farley - Reefkeeping.com Many would agree that reef tanks can be successful with pH between 7.8 – 8.5 NBS and daily swings as great as 0.5 NBS. Natural pH levels in our ocean...

www.reef2reef.com

If you are really looking to stabilize pH...

Tuning a Skimmer / CO2 Scrubber for pH Control

On my reefing journey, I found Kalkwasse + Skimmer + CO2 Scrubber to be very effective for bringing my pH from 7.8 - 7.9 to 8.26 - 8.36. I guess most people would just leave it at that. However, I wanted to be more efficient with the CO2 scrubbing material so I wanted to implement a...

www.reef2reef.com

 

[BiggestE22]

My experience is the exact opposite. With a scrubber, I never got more than about .05 or so benefit. Plus, you cannot really dial in more/less very easily.

With saturated kalk, I could dose to deadly levels of pH with ease. In fact when we are away and the house is empty, I have to dial back.

My "normal" rate is 3,600 ml per 24 hours. My APEX DOS pushes RODI into a larger kalk stirrer, which then gravity feeds to the sump. My program doses only 700ml during the light cycle and 2,900 during lights out. Works like a charm.

As an added benefit, it reduces my two-part dosing by half, to about 240ml per day.

I think maybe tank size may make a difference or maybe eval rates. I have a 52 gallon system and evaporate about 1.2 gallons a day. So I cannot add more Kalwasser top off water than that. I have good grow with 2 mp40s on reef crest at about 55%

 

[ScottB]

I think maybe tank size may make a difference or maybe eval rates. I have a 52 gallon system and evaporate about 1.2 gallons a day. So I cannot add more Kalwasser top off water than that. I have good grow with 2 mp40s on reef crest at about 55%

Agree. My skimmer is very undersized for this 300G growout system. Even in recirculating setup I just could not move the needle with the scrubber alone.

I have a lot of evaporation as these are shallow tanks with a great deal of surface turbulence.