Kalk reactor owners: pH swings?

[cr500_af]

I just recently (3 days ago) got my Kalk reactor online. I had been experiencing trouble keeping my alk up, and my pH was chronically low.

I seem to be getting PART of what I wanted... my daytime pH has gone from around 8.1 to 8.3 or so. So far, so good.

However, my nighttime pH (around 7.85 usually) hasn't changed enough to notice. So, my daily pH swing has actually gotten worse.

Anything I'm missing in this equation? I don't imagine this would be normal, but I also can't think of a reason why the night value would see an increase significantly after the daytime value does.

FWIW, even though I don't have a refugium in my sump anymore, I still run the sump light on a reverse cycle in an attempt to soften the swing.

Input welcomed, and thanks.

 

[jeffmuse]

I used a Kalk reactor for a while to try and keep my Alk and Calc. stable, but noticed similar results with my PH. Without the reactor my Ph swing was around 8.3 during the day to 8.0 in the evening, and with the reactor my Ph was 8.4 during the day and 8.1 at night. I also ran my refugium at night to counter act the day night cycle swing.

My kalk stirrer was tied into my ATO system, so as the water level dropped, fresh water was pushed into the reactor and deposited kalk into the sump. The ONLY thing that I can think is that being there is less evaporation in the evening, the ATO is not pushing as much kalk into the system at night. During the day, when the lights are on, there was a lot more kalk water entering the system via the ATO.

I have thought about setting up a kalk drip in the evening to see what effect a constant rate of kalkwasser would do with the lights off, but have not gotten around to it as of yet. I hope this helps!

 

[cr500_af]

It does... I have a BRS dosing pump and it would be pretty easy to dose some kalkwasser during the night as an experiment.

 

[mph84]

cr500_af;671595 wrote: I just recently (3 days ago) got my Kalk reactor online. I had been experiencing trouble keeping my alk up, and my pH was chronically low.

I seem to be getting PART of what I wanted... my daytime pH has gone from around 8.1 to 8.3 or so. So far, so good.

However, my nighttime pH (around 7.85 usually) hasn't changed enough to notice. So, my daily pH swing has actually gotten worse.

Anything I'm missing in this equation? I don't imagine this would be normal, but I also can't think of a reason why the night value would see an increase significantly after the daytime value does.

FWIW, even though I don't have a refugium in my sump anymore, I still run the sump light on a reverse cycle in an attempt to soften the swing.

Input welcomed, and thanks.

as far as running a sump light, isn't it photosynthesis that causes the ph to move?

 

[cr500_af]

mph84;671637 wrote: as far as running a sump light, isn't it photosynthesis that causes the ph to move?

I honestly don't know. I left it alone because a: it can't hurt and b: 90% of my tinkering with the tank happens at night, so having the light on is a plus.

 

[jeffmuse]

mph84;671637 wrote: as far as running a sump light, isn't it photosynthesis that causes the ph to move?

I have tried a couple of different scenarios with my sump lights... I have run the refugium/ sump lights opposite the day time lights and also tried running the sump lights 24/7.

I have not seen much of a difference in Ph swings between the two different lighting setups.

 

[markv]

Nighttime kalk dosing is the best way to help stabilize your pH. If you have a dosing pump hooked up to a float switch, just stick a light timer on it so that it only refills the sump at night. Provided you don't have crazy evaporation rates, there should be enough time in the evening to keep the sump level.

 

[smallblock]

have you tried a co2 scrubber Barry? It could only help IMO

 

[spiderman097]

I run my Kalk at night, and I'm usually asleep when it turns on, but i don't think it hurts/helps that much. You shouldn't worry about chasing numbers to much, seawater drops in PH naturally at night.

As algae goes through photosynthesis, Oxygen is released into the water, bringing up the PH of water. But, during nighttime, algae goes through cellular respiration and releases Carbon Dioxide into the water, thus reducing the ph.

 

[skriz]

Barry, without a refugium, the light won't affect ph at all.

I wouldn't worry too much about the ph swing, though.

 

[cr500_af]

Skriz;671704 wrote:
I wouldn't worry too much about the ph swing, though.

I'm going to anyway!

It's the last suspect in the "why won't my acros ever have polyp extension?" case.

All my other params are good, the SPS are growing and colored right, but there are literally acros in my tank that I've had for a year or more and DO NOT KNOW what color the polyps are because I've NEVER seen them.

 

[markv]

Agreed, a nighttime pH of 7.8 isn't too bad. I wouldn't worry about it.

 

[grouper therapy]

I would imagine that the evaporation rate is higher in the daytime if the lights are on therefore more kalk is being added
I Let kalk drip 24/7 and my PH is super stable.

 

[grouper therapy]

sorry Jeffmuse just read your post lol