Kalk not raising PH

[Floyd-]

I mixed in 3/4 tsp to a gallon for 5 gallons to try it out and my PH hasnt bumped at all. Should I just up the solution? I read that 1.5 tsp to a gallon is the max saturation.

 

[Randy Holmes-Farley Verified Community Expert]

Saturation may be higher, closer to 2 tsp per gallon, but most important is how much you added to the aquarium.

Also, be sure you are tracking alkalinity. You do not want to push it too high.

 

[Floyd-]

Saturation may be higher, closer to 2 tsp per gallon, but most important is how much you added to the aquarium.

Also, be sure you are tracking alkalinity. You do not want to push it too high.

Ill be checking alk tonight. I took my dosing pump offline to account for the added alk from the Kalk.
I was at about 9dkh last I checked.

 

[Randy Holmes-Farley Verified Community Expert]

Ill be checking alk tonight. I took my dosing pump offline to account for the added alk from the Kalk.
I was at about 9dkh last I checked.

Dosing 1.4% of the total water volume using saturated kalkwasser will boost ph instantly by about 0.6 pH units (too much at once). It then drops back over time as the tank pulls in more CO2. if you measure 24 h after dosing, you may see no net effect.

The pH effect is very roughly linear with the amount of hydroxide dosed (by kalkwasser or other means). if you dose only 0.14% of the water volume at once, the pH rise will be more like 0.06 pH units.

 

[doubleshot00]

I tried Kalk in my main display and my PH never changed. I switched to Red Sea Alk and it climbs every time i dose it.

 

[Floyd-]

Dosing 1.4% of the total water volume using saturated kalkwasser will boost ph instantly by about 0.6 pH units (too much at once). It then drops back over time as the tank pulls in more CO2. if you measure 24 h after dosing, you may see no net effect.

The pH effect is very roughly linear with the amount of hydroxide dosed (by kalkwasser or other means). if you dose only 0.14% of the water volume at once, the pH rise will be more like 0.06 pH units.

At the moment with the kalk at 3/4" tsp per gallon in my ATO my PH has not got over 7.83 in 2 days. Ill try bumping it up and going from there. Little bumps at a time.

 

[Floyd-]

I tried Kalk in my main display and my PH never changed. I switched to Red Sea Alk and it climbs every time i dose it.

Im currently using redsea alk and my PH never gets above 7.8-7.9

 

[doubleshot00]

Im currently using redsea alk and my PH never gets above 7.8-7.9

You monitoring it with an apex? I fi turn my skimmer off and dose and dose 2-3 ml you can see a huge jump. How much are you dosing per how many gallons of water volume?

 

[Randy Holmes-Farley Verified Community Expert]

I tried Kalk in my main display and my PH never changed. I switched to Red Sea Alk and it climbs every time i dose it.

That is probably because you spaced out the dosing for kalk and not the Red Sea. The pH effect of kalk is at least twice as much as that of any alk supplement that is not hydroxide per unit of alk added.

 

[Randy Holmes-Farley Verified Community Expert]

At the moment with the kalk at 3/4" tsp per gallon in my ATO my PH has not got over 7.83 in 2 days. Ill try bumping it up and going from there. Little bumps at a time.

Little bumps at a time is what is expected/desired from kalkwasser dosing.

That said, no alk dosing can be certain to overcome high CO2 entering the tank from high CO2 in the room.

 

[Floyd-]

You monitoring it with an apex? I fi turn my skimmer off and dose and dose 2-3 ml you can see a huge jump. How much are you dosing per how many gallons of water volume?

Yes monitored with Apex and double checked with Hanna PH. I have it setup on my stock ATO in my red sea tank. Its just a float valve drip feed. Should I have it plumbed into my reefdose instead?

 

[Floyd-]

That said, no alk dosing can be certain to overcome high CO2 entering the tank from high CO2 in the room.

I have tried the glass of water in and out of the house with air stone aerating and saw almost no difference. Maybe .03 at best. Does that indicate that the CO2 in the house isnt to blame?

 

[Randy Holmes-Farley Verified Community Expert]

I have tried the glass of water in and out of the house with air stone aerating and saw almost no difference. Maybe .03 at best. Does that indicate that the CO2 in the house isnt to blame?

No, it means there's a testing error somewhere (or inadequate aeration in the test). pH MUST rise on aeration with normal outside air when the pH is 7.83 and the alk is 7 dKH or more.

 

[doubleshot00]

That is probably because you spaced out the dosing for kalk and not the Red Sea. The pH effect of kalk is at least twice as much as that of any alk supplement that is not hydroxide per unit of alk added.

I few weeks ago my alk was low due to air in the dosing line so i dosed a lot of redsea alk at one time and the PH went way up fast. So i started to experiment and watch my PH with the skimmer off and every time the alk doses the PH goes up. IDK

KALK did nothing for my PH. I dosed for a month straight. I even put it in my ATO to see if that made a difference.

 

[Floyd-]

No, it means there's a testing error somewhere (or inadequate aeration in the test). pH MUST rise on aeration with normal outside air when the pH is 7.83 and the alk is 7 dKH or more.

Was 15 minutes of air stone enough? Maybe the Hanna PH needs to be calibrated again. Ill try the test again after a calibration.

 

[Sasquatchv]

Pen style pH probes should really be calibrated before every use.
Make sure temperature of tested fluid is the same between tests. pH pen should be temperature compensated, but, should doesn't mean is

 

[Floyd-]

Pen style pH probes should really be calibrated before every use.

Really? Wow! I only calibrate every 12th test or so.

 

[Sasquatchv]

Really? Wow! I only calibrate every 12th test or so.

Depend how much depends on it. My experience was rather negative with them. I would rather use trituration test or industrial grade probe(pricey and huge)

 

[Randy Holmes-Farley Verified Community Expert]

I few weeks ago my alk was low due to air in the dosing line so i dosed a lot of redsea alk at one time and the PH went way up fast. So i started to experiment and watch my PH with the skimmer off and every time the alk doses the PH goes up. IDK

KALK did nothing for my PH. I dosed for a month straight. I even put it in my ATO to see if that made a difference.

I do not doubt you observed that, but it is due to how you dosed it, not that the Red Sea product boosts pH more.

It is a simple chemical fact that hydroxide raises pH a bit more than twice as much as carbonate, and bicarbonate has a slight pH lowering effect. The Red Sea product is a carbonate product, so it has half the pH lowering as hydroxide per unit of alk dosed.

 

[Randy Holmes-Farley Verified Community Expert]

Was 15 minutes of air stone enough? Maybe the Hanna PH needs to be calibrated again. Ill try the test again after a calibration.

Maybe not. And as noted, recalibration may be in order.