Another kalkwasser question

[Jorge Linares]

I’ve been doing a lot of reading about kalkwasser and need some help. I live in the Northwest and our home has very high Co2. Ph hovers at 7.6 and after adding a Co2 scrubber gets to 7.9 but is too expensive to maintain. Fresh air line is not an option. I want to replace my 2part for kalkwasser via a dosing pump. I currently use Triton on a low damand of 6ml a day. My question is how much Kalk should I mix per gallon and how much of it should I dose.
Thanks

 

[Lasse]

Do you use Core 7 ?

Sincerely Lasse

 

[Randy Holmes-Farley Verified Community Expert]

Do you know how much that 6 mL a day translates to in dKH per day in your system?

A low alk demand tank (which you describe yours as) won't get that much boost from using hydroxide as an alk source (either in limewater/kalkwasser or a DIY two part using hydroxide) because you won't be adding much.

 

[Jorge Linares]

Do you use Core 7 ?

Sincerely Lasse

Yes Core7 Other methods

Do you know how much that 6 mL a day translates to in dKH per day in your system?

A low alk demand tank (which you describe yours as) won't get that much boost from using hydroxide as an alk source (either in limewater/kalkwasser or a DIY two part using hydroxide) because you won't be adding much.

I’m not sure what it translates to so I will stop dosing and measure the fall. Would even a the little demand I have now and the use of Kalk help with the ph coupled with Co2 scrubbing? I will be adding more lps & sps as quickly as possible.

 

[Lasse]

I asked because there is a trick you can use if you use Core7. The two alkalinity parts (3A and 3B) act like a pH boost too. I have a 80 gallon tank, but its rather mature with a demand of around 35 ml a day from each of the bottles. I dose 3A every hour between 20:00 to 03:00 - its 8 time and I dose 3*5 ml and 5*4 ml. I dose 3B between 04:00 to 12:00 - 8 times and the same amounts. My photosynthesis normally goes down around 20:00 and start normally around 12:00. Hence I dose during the time the pH tend to be low. In this way i have succeeded to have a night pH around 8.2 and the highest day pH can be around 8.35. I use carbon scrubbing too. before I started with Core 7 my night pH was around 8 and day pH around 8.3. I have a reversed fuge with Chaeto - light on between 22:00 to 10:00.

In your case the demand of Core 7 is low but if you can dose the 12 ml of alk (6 ml 3A and 6 ml 3B) in equal parts during the time you have the lowest pH and for a while use your CO2 scrubber too you may be able to stabilize you pH in a way that you can introduce more stony corals - you will sooner or later have a demand that allow you to have a pH like mine.

Sincerely Lasse

 

[Jorge Linares]

I asked because there is a trick you can use if you use Core7. The two alkalinity parts (3A and 3B) act like a pH boost too. I have a 80 gallon tank, but its rather mature with a demand of around 35 ml a day from each of the bottles. I dose 3A every hour between 20:00 to 03:00 - its 8 time and I dose 3*5 ml and 5*4 ml. I dose 3B between 04:00 to 12:00 - 8 times and the same amounts. My photosynthesis normally goes down around 20:00 and start normally around 12:00. Hence I dose during the time the pH tend to be low. In this way i have succeeded to have a night pH around 8.2 and the highest day pH can be around 8.35. use carbon scrubbing too. before I started with Core 7 my night pH was around 8 and day pH around 8.3. I have a reversed fuge with Chaeto too - light on between 22:00 to 10:00.

In your case the demand of Core 7 is low but if you can dose the 12 ml of alk (6 ml 3A and 6 ml 3B) in equal parts during the time you have the lowest pH and for a while use your CO2 scrubber too you may be able to stabilize you pH in a way that you can introduce more stony corals you will sooner or later have a demand that allow you to have a pH like mine.

Sincerely Lasse

Good tips. I mostly dose alk during the day with a Coral Box Doser. I have a cheato reactor on reverse lighting. Even with this my ph only gets to 7.9 and occasionally 8.

 

[Lasse]

How do you measure pH?

Sincerely Lasse

 

[Jorge Linares]

How do you measure pH?

Sincerely Lasse

Handheld meter.

 

[Randy Holmes-Farley Verified Community Expert]

In terms of dosing hydroxide, adding 1.4 dKH all at once will instantly boost pH by about 0.6 pH units. Then over a period of hours the pH drops back as the tank sucks in CO2. If you only dose a small amount, like 0.2 dKH per day, the pH boost spread over the whole day will be minimal. It is even smaller using carbonate, and there’s no boost using bicarbonate.

 

[Jorge Linares]

In terms of dosing hydroxide, adding 1.4 dKH all at once will instantly boost pH by about 0.6 pH units. Then over a period of hours the pH drops back as the tank sucks in CO2. If you only dose a small amount, like 0.2 dKH per day, the pH boost spread over the whole day will be minimal. It is even smaller using carbonate, and there’s no boost using bicarbonate.

I see. Is 1.4 dKH 2 teaspoons per gallon. I’ve stopped the dosing and tested it at 8.8. I’ll check n 24hrs.

 

[Lasse]

Have you calibrate the ph meter with 7 and 9 (10). It should be a calibration for 7 and one for the slope (4 or 9(10)) Its not enough to do an one point calibration.

Sincerely Lasse

 

[Jorge Linares]

I use three points. 4.01, 6.86 and 9.18.

 

[Randy Holmes-Farley Verified Community Expert]

I see. Is 1.4 dKH 2 teaspoons per gallon. I’ve stopped the dosing and tested it at 8.8. I’ll check n 24hrs.

It depends on how much liquid volume you add to what volume tank. There are calculators around for easy determination.

 

[Jorge Linares]

It depends on how much liquid volume you add to what volume tank. There are calculators around for easy determination.

You’re right. Stupid question.

 

[Lasse]

I'm rather comfortable with electronic pH measurements but have never heard about a 3 point calibration for cheap meters. Can you please take a pic of the calibration instructions - maybe I learn something new.

Sincerely Lasse

 

[Jorge Linares]

The instructions say to use two points and you adjust with a screw. It’s not the best but close. I used three just to get closer.

 

[Lasse]

Is it an automatic calibration - i. e. It ask you to put into 6.83 - adjust with the screw - confirm and it ask you to put into next 9.xx - adjust an confirm?

Sincerely Lasse

 

[Jorge Linares]

No. You match the solution by adjusting the screw.

 

[Lasse]

I´m confused because this feels very strange. A true two point calibration (which you need) normally include an automatic process or two adjustment screws (or two knobs).

With the automatic process the meter asks you first to put the electrode in solution 1 (most of the meters is it pH 7) (the value of solutions - you normally can choose by yourself). After a wait time – confirm and the meter ask you for solution 2 and further on

Non automatic pH meters with a true two calibration method have two screws or knobs - one for adjust pH 7 and one for adjust the slope.

In an earlier thread I have tried to explain how this electronical pH meters work. Please read here

https://www.reef2reef.com/threads/ph-8-6-consistently-without-dosing.368833/#post-4548663

With this meter – I would not trust the readings – especially around 8. For me it looks like the calibration of this meter is a joke – but I can be wrong because I do not use this type of meters and have not any experiences of these cheap meters.

The whole problem can be cause of wrong figures – please try to confirm your pH with a real pH meter newly calibrated. If you shall transport the sample – fill up to the edge of the sampling vessel and put the lid on. .Analyse rather fast – pH change during storage.

Sincerely Lasse

 

[Jorge Linares]

I´m confused because this feels very strange. A true two point calibration (which you need) normally include an automatic process or two adjustment screws (or two knobs).

With the automatic process the meter asks you first to put the electrode in solution 1 (most of the meters is it pH 7) (the value of solutions - you normally can choose by yourself). After a wait time – confirm and the meter ask you for solution 2 and further on

Non automatic pH meters with a true two calibration method have two screws or knobs - one for adjust pH 7 and one for adjust the slope.

In an earlier thread I have tried to explain how this electronical pH meters work. Please read here

https://www.reef2reef.com/threads/ph-8-6-consistently-without-dosing.368833/#post-4548663

With this meter – I would not trust the readings – especially around 8. For me it looks like the calibration of this meter is a joke – but I can be wrong because I do not use this type of meters and have not any experiences of these cheap meters.

The whole problem can be cause of wrong figures – please try to confirm your pH with a real pH meter newly calibrated. If you shall transport the sample – fill up to the edge of the sampling vessel and put the lid on. .Analyse rather fast – pH change during storage.

Sincerely Lasse

Thanks for sharing that and it really help clear that up. This was the cheapest meter on Amazon. I will be upgrade now and thanks. Now there goes more money .