Folks who dose kalk at night, do you dose during the day?

[BAMatter]

If the goal is to prevent the nightly low, which is a reasonable goal, I'd dose only at night, spread out through the night.

If the goal is to boost calcification rate, then dosing during the day may actually help that more since higher pH may boost calcification, which seems to mostly happen during the day.

I don't think trying to keep the pH at 8.30 to 8.31 is necessarily going to work. If the pH is 8.3 at 11 AM, I think there's a good chance the pH will go higher even with no additions.

I also think that trying to see a visible difference between a reef tank tank at pH 8.2 and the same reef tank held at pH 8.3, or varying between pH 8.2 and 8.3 may be challenging.

Oh yea, for sure night time dosing. Sorry for any misunderstanding. To clarify, I dose around 2500mls of Kalk from 10:00pm-10:00 and dose Triton Core 7 the opposite 12 hours. Overnight, I’ve dosed both PH based, as well as constant drip (3.5ml/min) on that volume of kalk. The drip gives me a downward trend PH, from mid 8.3’s down to 8.2 at its lowest before lights come on again. But I can dose ROUGHLY that same amount +/- and hold a PH line at 8.30-8.32 when it doses from a 30ml/min doser. I’m just trying to lock in the better way to do it since I don’t have a large variance in amount dosed PH based. My PH always climbs to almost 8.40+ during the day when I’m dosing 2 part.

 

[Sisterlimonpot]

True saturation is about 12.54 at 25 deg C,

Where didb12.44 come from?

this sort of makes sense, I use a 12.46 buffer to calibrate my kalk pH probe, then when I place it back in the reactor it goes to ~12.50.

I just purchased another bottle and concluded that it was a bad batch.

 

[Randy Holmes-Farley]

The pH depends strongly on the temperature, but in looking closely to answer that question, it's possible that my value quoted in my limewater paper (12.54) is a typo and it really should be 12.454 at 25 deg C. Since I wrote it 18 years ago, I just don't recall.

I find more papers referring to 12.45 than other values when I look up saturated calcium hydroxide as a secondary pH standard.

Here's a set of data from 1962 when folks were devising pH standards:

deg C pH
20 12.627
25 12.454
30 12.289

Revised Standard Values for pH Measurements from 0 to 95 °C

Seven standard solutions serve to fix the NBS conventional activity scale of pH (termed pH[s] ) from 0 to 95° C. The original emf data have been re-examined and the values of the acidity function p(α[H] γ[Cl] ), from which pH[s] ...

www.ncbi.nlm.nih.gov

 

[Randy Holmes-Farley]

Oh yea, for sure night time dosing. Sorry for any misunderstanding. To clarify, I dose around 2500mls of Kalk from 10:00pm-10:00 and dose Triton Core 7 the opposite 12 hours. Overnight, I’ve dosed both PH based, as well as constant drip (3.5ml/min) on that volume of kalk. The drip gives me a downward trend PH, from mid 8.3’s down to 8.2 at its lowest before lights come on again. But I can dose ROUGHLY that same amount +/- and hold a PH line at 8.30-8.32 when it doses from a 30ml/min doser. I’m just trying to lock in the better way to do it since I don’t have a large variance in amount dosed PH based. My PH always climbs to almost 8.40+ during the day when I’m dosing 2 part.

I don't really see a rationale for a substantial difference in pH with those two different modes of dosing the same total amount both spread out over the same total period.

Where is the pH measured in relation to where the limewater is added?

In any case, I'd just pick whichever one seems most convenient and useful.

 

[BAMatter]

I don't really see a rationale for a substantial difference in pH with those two different modes of dosing the same total amount both spread out over the same total period.

Where is the pH measured in relation to where the limewater is added?

In any case, I'd just pick whichever one seems most convenient and useful.

PH is measured in the section of the sump before where Kalk is dosed into, so it needs to get cycled through the display and back before it gets a higher PH reading. The yellow circle is dosing PH based, the red are just dripping constant.

 

[DrMMI]

My alk tends to rise about 0.3 dkh between 12am-6am without any dosing and my ph dips down to 7.7. Would dosing kalk at night make my alk swing even higher?

 

[ReefPit]

I use a fully saturated kalk Solution hooked up to a PH controller with the meter in the display tank (40 gallon breeder, no lid). The PH controller kicks on around midnight and goes to about noonish, I drip ~2.2 ml/min. I don’t do ATO as the evaporation and PH controller are close enough. I almost never need to add RO, salinity stays at 1.026. I go through ~<1 gallon kalk solution every 48 hours.

I do weekly 10% water changes and have been using Reef Crystals. Between the kalk drip and Reef Crystals, the calcium is slowly drifting up, approaching 500. I’m switching from the Reef Crystal to the standard Instant Ocean, the trend is obvious and I suspect this will allow for some additional control.

Anyways, the Kalk solution tied to PH seems to fit into a nice rhythm supporting calcium, PH, alk, and evaporation (salinity).

 

[Randy Holmes-Farley]

My alk tends to rise about 0.3 dkh between 12am-6am without any dosing and my ph dips down to 7.7. Would dosing kalk at night make my alk swing even higher?

Alk does not normally increase like that on its own. I suspect it is a measurement issue if you are certain you are dosing none.

 

[WhatCouldGoWrong71]

I am currently dosing 120 ML of 2 part 24/7 (Part C is x2 of that). I would like to start dosing kalk over night to stabilize my PH. I came to this forum to ask 2 questions, this read has to do with one of those, I will post both here in hopes that both can be answered.
If 50ML of BRS 2 part alk is equal to 2.3 liters of lime water -

1) Should I start with 25% of my 24 hour dosing amount for 2 part and convert that amount to kalk to start dosing over a 10 hour period? So, 30 ML of my BRS 2 part would be 1,380 ML of kalk. If I tell my DOS unit to dose 1,380 ml over that 10 hour period, it will dose 46 - 30 ML doses. Does this sound right? Is there a way to tell my DOS to drip constantly for x amount of minutes then pause for x amount of minutes and start again? I feel like it is operator error.

2) As it relates to standard 2 part dosing schedules. I currently dose alk on even hours and cal on odd hours. Can I simply spread both out over the entire day (similar to the kalk scheduling example) and not worry about them dosing too closely together?

What 25% of Kalk spread over 10 hours would look like:

Current PH trends:

 

[Mikeltee]

I set my kalkstirrer to cycle for 60 seconds every hour. I set my ATO to come on for 5 minutes before every hour and shut off when the high sensor is triggered. It helps to raise my pH. Here's a comparison with days with kalk vs without. My sump was full after a water change and didn't topoff.

 

[Mikeltee]

In what way?

It costs more so the placebo effect makes those corals POP!

 

[bobnicaragua]

Continuous dosing of kalk 24/7 on a Versa dosing pump. I then dose BRS 2 part and Tropic Marin Part C as well

I do the exact same thing.

 

[DrMMI]

Alk does not normally increase like that on its own. I suspect it is a measurement issue if you are certain you are dosing none.

Yeah it's weird. It happens on both my tanks. I usually dose alk 6:30am-11:45am and 6:30pm to 11:45pm because if I dose 12pm-6pm and 12am-6am, it sky rockets.

 

[Randy Holmes-Farley]

The changes are quite small there. I would not be sure it is a real effect as opposed to pH effects messing with the measurement,

 

[Troylee]

I use a fully saturated kalk Solution hooked up to a PH controller with the meter in the display tank (40 gallon breeder, no lid). The PH controller kicks on around midnight and goes to about noonish, I drip ~2.2 ml/min. I don’t do ATO as the evaporation and PH controller are close enough. I almost never need to add RO, salinity stays at 1.026. I go through ~<1 gallon kalk solution every 48 hours.

I do weekly 10% water changes and have been using Reef Crystals. Between the kalk drip and Reef Crystals, the calcium is slowly drifting up, approaching 500. I’m switching from the Reef Crystal to the standard Instant Ocean, the trend is obvious and I suspect this will allow for some additional control.

Anyways, the Kalk solution tied to PH seems to fit into a nice rhythm supporting calcium, PH, alk, and evaporation (salinity).

Kalk is most likely adding the calcium and bringing it up.. been there done that! Lol.. mine got up to 600 with kalk alone and no water changes so I switched to sodium hydroxide “alk only” till it dropped to 420 and back to kalk now.

 

[DrMMI]

The changes are quite small there. I would not be sure it is a real effect as opposed to pH effects messing with the measurement,

Thanks Randy. I'll try to dose a little bit of kalk overnight to see if the pH bump helps stabilize the alkalinity.