How much kalkwasser to dose ?

[paulrathor92]

My tanks alkalinity is dropping .1 each day. Want to start dosing kalkwasser. Sick of having to add sodium bicarbonate by hand daily. My question is how much kalkwasser should I dose. I have total of 21 gallons of tank volume.

 

[elorablue]

Do you do water changes? Every week? What is your alk right before a wc and what is it right after?
I'm wondering myself if I need to start dosing.
My alk starts off at 8.5 right after a wc and drops to 7.5 right before my weekly 15% wc.
All is good in the tank (20g cube) and sps are growing so I dunno if this drop is acceptable or not

 

[paulrathor92]

I've never let it drop below 7. Usually keep it right at 8 I've been testing every day seeing what my daily consumption is. But If I didn't add anything to replace used alk it would be 7.3 from 8.

 

[elorablue]

ok. I'll be interested to hear any replies.

 

[RobB'z Reef]

My tanks alkalinity is dropping .1 each day. Want to start dosing kalkwasser. Sick of having to add sodium bicarbonate by hand daily. My question is how much kalkwasser should I dose. I have total of 21 gallons of tank volume.

Edit- math error! Oops sorry, was distracted, should have been 65ml not 265.

My swag at it is around 265ml per day of fully saturated kalk to counter .1 dKH pet day in 21 gallons.

Check the math, but the guidelines I use are as follows:

Base formulation: adding 1.25% of total volume (tank) of saturated solution will add .5meq/L of alkalinity (1.4dKH) and 10ppm Calcium.

 

[blasterman]

If you dose dry sodium bicarbonate (baking soda) kalk is pretty easy to calculate. Its approx half the strength of dry baking soda per volume to hit desired dKH. So, whatever affect 1/2 teaspoon of baking soda does kalk powder requires a full teaspoon to have the same dKH affect. The rest forms calcium, although I've found 2x kalk not as good as 1x calcium chloride at keeping calcium.

"Fully saturated" is different amounts to different people.

 

[RobB'z Reef]

If you dose dry sodium bicarbonate (baking soda) kalk is pretty easy to calculate. Its approx half the strength of dry baking soda per volume to hit desired dKH. So, whatever affect 1/2 teaspoon of baking soda does kalk powder requires a full teaspoon to have the same dKH affect. The rest forms calcium, although I've found 2x kalk not as good as 1x calcium chloride at keeping calcium.

"Fully saturated" is different amounts to different people.

I thought fully saturated means only one thing mathematically? I think it's 6g/4L @ 77 degrees. I might be a bit off on the weight... Or around 2 tsp/gal.

 

[Oregon Grown Reef]

I take all of the guess work out and use this. https://reef.diesyst.com/chemcalc/chemcalc.html

Just choose saturated lime water to find out your dosage.

 

[paulrathor92]

I have the same system volume 21 gallons and am losing .1 dkh a day as well. So should I dose 65ml of fully saturated solution or 265ml?

 

[Randy Holmes-Farley Verified Community Expert]

I have the same system volume 21 gallons and am losing .1 dkh a day as well. So should I dose 65ml of fully saturated solution or 265ml?

It doesn't work exactly like that, but that's a decent first starting dose.

 

[JAWSIII]

It doesn't work exactly like that, but that's a decent first starting dose.

Randy. Sorry if I am hijacking this thread. I couldn’t figure a way to PM you directly.

I have a 65 DT with a 20 gallon sump. That is a little over a year old. I have struggled to keep my PH up , it usually hovers around 7.7. I have tried running a CO 2 xcrubber from BRS it gave me increase up to 7.8. I have tried and currently use a fresh airline from outside direct into skimmer still 7.7 with or without the fresh air. I have the surface of my tank very agitated with 2 wave makers and return from sump all making lots of breaks.

I have never tried Kalk until last night after reading your very extensive article. Yesterday I went to LFS and purchased Seachem Kalk and the pieces I needed to build a DIY dripper. I mixed the Kalk using 2 tsp to 1 gallon RO and let settle for about 4 hours. I poured off only the clear mixture into my dripper container and started a drip at about 9 pm last night.

I tested 3 things before I started the drip into the system at 9 pm and the same at 7am

Calcium last night 440 This morning 450
DKH last night 8.5. This morning 9.3
PH last night 7.7 This morning 7.9

I have the drip set pretty slow one drip about every 4 seconds. It took 10 hrs to drip 3/4 of a gallon

my questions are.

should I expect a Higher PH increase than .2 ? Are the other values consistent with your experience as far as increase in value and are they too high? Should I continue the Kalk? Increase speed of drip? Or try something else?

my complete water parameters Before starting the Kalk were

Calcium 440
DKH 8.5
PH 7.7
Mag 1550
Salinity 1.025
Phosphate 0.03
Nitrate 10-15 (aqua forest)
Amonia undetectable
Nitrite undetectable


BTW the Kalk solution tested at PH 12

thanks for your help.

 

[uhgster1]

I have a 65 gallon with a 20 gal sump. I dose my kalk with my ato. 3 years and running. And I dose All for Reef. My ph stays at a consistent 8.3. Try dosing the kalk with your ato. Another thing I do is that my overflow flows straight into the sump. If the noise doesn’t bother you it’s more water movement for gas exchange.

I’m not home right now but when I get there I’ll show you how simple my sump is.

 

[Acroporaguy]

Don't dose kalk via an ato, that's a bad idea. As the seasons change, your evaporation rate will as well.

 

[Randy Holmes-Farley Verified Community Expert]

Randy. Sorry if I am hijacking this thread. I couldn’t figure a way to PM you directly.

I have a 65 DT with a 20 gallon sump. That is a little over a year old. I have struggled to keep my PH up , it usually hovers around 7.7. I have tried running a CO 2 xcrubber from BRS it gave me increase up to 7.8. I have tried and currently use a fresh airline from outside direct into skimmer still 7.7 with or without the fresh air. I have the surface of my tank very agitated with 2 wave makers and return from sump all making lots of breaks.

I have never tried Kalk until last night after reading your very extensive article. Yesterday I went to LFS and purchased Seachem Kalk and the pieces I needed to build a DIY dripper. I mixed the Kalk using 2 tsp to 1 gallon RO and let settle for about 4 hours. I poured off only the clear mixture into my dripper container and started a drip at about 9 pm last night.

I tested 3 things before I started the drip into the system at 9 pm and the same at 7am

Calcium last night 440 This morning 450
DKH last night 8.5. This morning 9.3
PH last night 7.7 This morning 7.9

I have the drip set pretty slow one drip about every 4 seconds. It took 10 hrs to drip 3/4 of a gallon

my questions are.

should I expect a Higher PH increase than .2 ? Are the other values consistent with your experience as far as increase in value and are they too high? Should I continue the Kalk? Increase speed of drip? Or try something else?

my complete water parameters Before starting the Kalk were

Calcium 440
DKH 8.5
PH 7.7
Mag 1550
Salinity 1.025
Phosphate 0.03
Nitrate 10-15 (aqua forest)
Amonia undetectable
Nitrite undetectable


BTW the Kalk solution tested at PH 12

thanks for your help.

The pH rise is reasonable, but my concern is the rise in alkalinity. if it keeps up, alkalinity would soon be too high. You may need to adjust the amount of kalkwasser added to stabilize the alk, then see what benefit that had on pH.

 

[Randy Holmes-Farley Verified Community Expert]

Don't dose kalk via an ato, that's a bad idea. As the seasons change, your evaporation rate will as well.

I personally wouldn't characterize it as a "bad" idea (I did it apparently OK for 20 years), but I do agree that a dosing pump on a timer set to deliver just below the evaporation rate can lead to greater alk stability.

 

[JAWSIII]

The pH rise is reasonable, but my concern is the rise in alkalinity. if it keeps up, alkalinity would soon be too high. You may need to adjust the amount of kalkwasser added to stabilize the alk, then see what benefit that had on pH.

I checked this morning the dosing has been consistent using a mixture of 2 teaspoons per gallon of RO water and dripping in roughly 1 gallon every 12 hrs.

dkh 10.2
Calcium 455
PH 7.8

should I continue? Or is the KH too much?

am I just going to have to live with 7.7-7.9 Ph? I swear I tried everything short of moving to a new house. And my house is not new because people have said due to better insulation that holds more CO2. But my house was built in yhe 60’s

 

[Randy Holmes-Farley Verified Community Expert]

The alk is OK now, but seems to rise with each test. I'd slightly reduce the amount dosed.

 

[JAWSIII]

Ok. Will do. Maybe a dumb question but here goes..

If I lower the amount to say 1 tsp per gallon and that helps with allk increase. Does that also mean it will not increase the PH? If dosing the Kalk ( in any amount) doesn’t raise the PH then should I just go back to dosing calcium alone as needed?

 

[Randy Holmes-Farley Verified Community Expert]

Ok. Will do. Maybe a dumb question but here goes..

If I lower the amount to say 1 tsp per gallon and that helps with allk increase. Does that also mean it will not increase the PH? If dosing the Kalk ( in any amount) doesn’t raise the PH then should I just go back to dosing calcium alone as needed?

Less concentrated kalkwasser has a smaller alkalinity boost and a smaller pH boost for the same volume added.

 

[Tommyrowe]

I have a 65 gallon with a 20 gal sump. I dose my kalk with my ato. 3 years and running. And I dose All for Reef. My ph stays at a consistent 8.3. Try dosing the kalk with your ato. Another thing I do is that my overflow flows straight into the sump. If the noise doesn’t bother you it’s more water movement for gas exchange.

I’m not home right now but when I get there I’ll show you how simple my sump is.

Wow!! Stunning. I dose all for reef and am now starting kalk. What doesage shouls i start with? My tank uses .1 of alk per day