Better to dose small amount of fully saturated Kalk, or more of a weaker concentration when trying to raise PH

Pat613

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Is it better to dose less fully saturated kalk, or more of a non-saturated solution, to raise pH? I have a strong suspicion it doesn't matter, but figured I'd ask :)

My alk is climbing but pH isn't, so I'm curious if a lower saturation, dosed over a longer time period, would be any better. My pH is 7.9 with a CO2 scrubber, dosing 100ml full saturation in 24 doses over 24 hours, in a 20g tank. Window is open. CO2 meter reads 433.

I'm dosing 2ml/day of nopox to get my nitrates down (currently 40ppm) and realize this will negatively impact pH, but want to minimize the pH hit.

Thanks,
PJ
 
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kriskool123

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I noticed the best way to raise ph is with good media on the scrubber. My set up I had 7.9-8.1 with ice cap or BRS media. When I switch to Jorvet soda like in my co2 scrubber my ph went to 8.1-8.3.

i tried everything to get ph to rise since I have 3 dogs and 2 people in a row house and changing the media to this worked the best out of anything!
 

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Indeed, if you want a little quicker bump you can use sodium carbonate, but that stuff is more caustic and you can over-do it. Sounds like you are doing everything else to mitigate CO2, perhaps it's just a bit more time. Fortunately, I've not had pH issues but that's likely because my doors and windows are typically open 24/7-365, it's good to live at the beach :)
 
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I noticed the best way to raise ph is with good media on the scrubber. My set up I had 7.9-8.1 with ice cap or BRS media. When I switch to Jorvet soda like in my co2 scrubber my ph went to 8.1-8.3.

i tried everything to get ph to rise since I have 3 dogs and 2 people in a row house and changing the media to this worked the best out of anything!
Yeah that was Icecap media, just refilled with 2LF stuff a few minutes ago, hopefully that gets a better boost. 2 people and 1 giant cat (maine coon) in a condo here. I'll see if jorvet is available in Canada, thanks for the tip!
 
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Kalk not great for making pH adjustments, try some sodium bicarb.

Sodium bicarbonate lowers the pH of seawater.

Hydroxide is the higher possible pH boost per unit of alk added. It need not be kalkwasser. Sodium hydroxide can also be used.
 

Randy Holmes-Farley

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Won't sodium bicarb increase my alk, but with less of a pH bump? Sorry, sorting through all the conflicting info can be a bit :face-with-spiral-eyes:. Thanks, I'm looking into bicarb :).

Very bad choice. It lowers pH.

ALL pH boosting agents raise alk, with hydroxide being best, carbonate being second with half the boost per unit of alk added, and bicarbonate actually lowering pH when first added.
 
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Is it better to dose less fully saturated kalk, or more of a non-saturated solution, to raise pH? I have a strong suspicion it doesn't matter, but figured I'd ask :)

My alk is climbing but pH isn't, so I'm curious if a lower saturation, dosed over a longer time period, would be any better. My pH is 7.9 with a CO2 scrubber, dosing 100ml full saturation in 24 doses over 24 hours, in a 20g tank. Window is open. CO2 meter reads 433.

I'm dosing 2ml/day of nopox to get my nitrates down (currently 40ppm) and realize this will negatively impact pH, but want to minimize the pH hit.

Thanks,
PJ

So I found that dripping Kalkwasser to give a more consistent and prolonged pH bump.

However, your Kalkwasser can only be used to your evaporation limit and Alk consumption.

You mentioned 100ml of kalkwasser...that is very little unless your tank is 10 litter. My 400L tank (~100gal) uses 4000ml of kalkwasser a day...which is just below the evaporation limit. Most evaporation limits are arount 1%.
 
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Pat613

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So I found that dripping Kalkwasser to give a more consistent and prolonged pH bump.

However, your Kalkwasser can only be used to your evaporation limit and Alk consumption.

You mentioned 100ml of kalkwasser...that is very little unless your tank is 10 litter. My 400L tank (~100gal) uses 4000ml of kalkwasser a day...which is just below the evaporation limit. Most evaporation limits are arount 1%.
Thanks, that helps a bunch! My evaporation is 1000ml, but at full saturation that'd nuke my tank. So a less kalk, but dosing more would be worth trying until my corals can suck up the alk? Because when I raise the pH with 2 part, my alk is .5 drop/day. Dosing full strength kalk boosts the alk too high, but the pH bump is too transient, so my alk consumption drops to almost nothing.
 

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Thanks, that helps a bunch! My evaporation is 1000ml, but at full saturation that'd nuke my tank. So a less kalk, but dosing more would be worth trying until my corals can suck up the alk? Because when I raise the pH with 2 part, my alk is .5 drop/day. Dosing full strength kalk boosts the alk too high, but the pH bump is too transient, so my alk consumption drops to almost nothing.

A 1% replacement with fully saturated kalkwasser will provide roughly 1dKH. So you should be dripping 500ml of kalkwasser a day.

I wouldn't try to play around with less than saturated kalkwasser...it'll be hard to get it right.
 
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Just dose fully saturated kalk to meet alk and calcium needs and use a regular ato to fill the rest of the top off needs. This will work until you need more alk/calc than the kalkwasser can provide which is limited by that 1% u all are talking about.
also I drip it all day with about 70-80% being dripped in at night for pH bc I feel as if that drop at night will determine the top end of your pH graph the next day when your lights are on
 
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Just dose fully saturated kalk to meet alk and calcium needs and use a regular ato to fill the rest of the top off needs. This will work until you need more alk/calc than the kalkwasser can provide which is limited by that 1% u all are talking about.
also I drip it all day with about 70-80% being dripped in at night for pH bc I feel as if that drop at night will determine the top end of your pH graph the next day when your lights are on
When I do this, the pH stays low and alk consumption stops.
 

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I agree that the pH boost is transient when adding high pH additives because the tank draws in CO2 to come back toward equilibrium.

if demand for alk is low, you won't get much pH boost since the boost is about linear with the amount of alk added.

It's a more sophisticated and complex question whether the average pH over the day is higher or lower with the same amount spread out more, but the answer will be higher more spread out, even though the average increase is quite low.

The question is similar to the standard analogy of a cooling cup of hot coffee.

Suppose the coffee is 180 deg F and you can only drink it when it hits 130 deg F.

Will you get to drinkable faster if you put the room temperature cream into it right way, or only after it has cooled a while.

The answer is waiting, because the rate of heat loss from the coffee is greater when the temp difference between the room air and the coffee is greater.

Likewise, if you dump all the hydroxide in at once, you set up a bigger draw for CO2 to enter and stay in the water than if you spread the hydroxide out over many hours.

I suspect the difference is small, however. nevertheless, it is usually best to spread out hydroxide dosing so as to not get pH too high when it is first added, if for no other reason.
 
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Pat613

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I agree that the pH boost is transient when adding high pH additives because the tank draws in CO2 to come back toward equilibrium.

if demand for alk is low, you won't get much pH boost since the boost is about linear with the amount of alk added.

It's a more sophisticated and complex question whether the average pH over the day is higher or lower with the same amount spread out more, but the answer will be higher more spread out, even though the average increase is quite low.

The question is similar to the standard analogy of a cooling cup of hot coffee.

Suppose the coffee is 180 deg F and you can only drink it when it hits 130 deg F.

Will you get to drinkable faster if you put the room temperature cream into it right way, or only after it has cooled a while.

The answer is waiting, because the rate of heat loss from the coffee is greater when the temp difference between the room air and the coffee is greater.

Likewise, if you dump all the hydroxide in at once, you set up a bigger draw for CO2 to enter and stay in the water than if you spread the hydroxide out over many hours.

I suspect the difference is small, however. nevertheless, it is usually best to spread out hydroxide dosing so as to not get pH too high when it is first added, if for no other reason.
Thank you, thank you, thank you :). This is clicking for me now :)
 

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I noticed the best way to raise ph is with good media on the scrubber. My set up I had 7.9-8.1 with ice cap or BRS media. When I switch to Jorvet soda like in my co2 scrubber my ph went to 8.1-8.3.

i tried everything to get ph to rise since I have 3 dogs and 2 people in a row house and changing the media to this worked the best out of anything!
Agreed. I went with the “medical grade” anesthesia version from Amazon and saw a bit of an increase from the reef version too.
 

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