High Tide Aquatics

Kalkwasser & ph anecdote

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richiev

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My 30gal frag tank I thought my pH probe was broken, since my pH had been drifting down for awhile. Through a random series of events I ended up testing against a second pH probe that I calibrated, and turned out that nope, my pH really was just drifting down. This likely was due to my reduction in skimming, but could be the little office space that tank is might have high CO2 during these cold periods.

The tank itself is managed with All-For-Reef, dosed 3 times a day. It doesn't have tight controls there then, and already would have a smooth release of Alk & Ca & ...

Because of all that, I decided to toss some Kalk into my ATO water, allowing me to drop my AFR dosing a bit, keep the release of everything smooth, and see what'd happen with pH. Pretty interesting effects:

fragtankpi.png


I have don't know this change to be particularly good or bad (though I wish it'd of switched a little slower), but cool that it brought my pH up that easily.

This is from Seachem's Kalk, added at around 2/3rds the base concentration they say.
 
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JVU said:
Also, All For Reef can definitely lower pH, since it is converted to the active components by bacterial metabolism (which lowers pH). This is one of the main reasons not to use it for a large consumption tank. I found out the hard way a couple years ago.
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Good to know! I'm dosing 20ML/day in my 40gal. I wonder how much of an impact it has.
 
How are you Alk/Calc readings? My alk/calc is pretty steady with just kalk as ATO. Though I dose a bit of alk. My CA is through the roof though.
 
Kalk + CO2 scrubber is the only way I've found to keep my pH close to natural sea water (8.3). Anecdotally speaking, my corals seem to be healthier and growing faster.
 
Vincerama2 said:
How are you Alk/Calc readings? My alk/calc is pretty steady with just kalk as ATO. Though I dose a bit of alk. My CA is through the roof though.
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If that's directed at me, I've only been doing kalk for about 72hrs so I don't have data yet.

I think though you have a typo in there. I'm not sure what you mean by it's steady, but you have to dose alk and your Calcium is off.
 
@Vincerama2, I've had a similar experience with kalk over the past month. Two tanks are chewing through alk, so I started kalk, which almost stabilized alk, so now I add just a little alk with kalk. But now calcium is rising....near 500 from 430-ish last month. Tank is looking fine, but I don't like the steady rise of Cal over that time...and still needing alk....so they arent consuming the two in equal parts as I had expected.

Is that normal?

On reading the ATO kalk method instructions it also seems to say that we should avoid taking from the bottom 1" of the solution....and I don't think I was doing that.

Any insight is greatly appreciated.

I had been using AFR but noticed the Alk still dropping quickly...so shifted to kalk+Alk. Seems several of us have tanks and their chemistry in just about the same place right now.
 
Prestondeeply said:
@Vincerama2, I've had a similar experience with kalk over the past month. Two tanks are chewing through alk, so I started kalk, which almost stabilized alk, so now I add just a little alk with kalk. But now calcium is rising....near 500 from 430-ish last month. Tank is looking fine, but I don't like the steady rise of Cal over that time...and still needing alk....so they arent consuming the two in equal parts as I had expected.

Is that normal?

On reading the ATO kalk method instructions it also seems to say that we should avoid taking from the bottom 1" of the solution....and I don't think I was doing that.

Any insight is greatly appreciated.

I had been using AFR but noticed the Alk still dropping quickly...so shifted to kalk+Alk. Seems several of us have tanks and their chemistry in just about the same place right now.
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You can have situations where organic acids in the tank chew up alkalinity but since it's not going into coral skeletons in a balanced ratio, you'll have a climbing Ca level until it precipitates out. I'd slowly raise your alk to your ideal level without adding back any Ca.

This article is great about explaining the why and what to fix: https://reefkeeping.com/issues/2004-12/rhf/index.php
 
Kalk solution (lime water) is stable at max saturation. You can mix up asuch as you need in a bucket and dose it like any other additive. Toss out the sludge.

I don't recommend using the ATO methind since top off volume is inconsistent.
 
Darkxerox said:
You can have situations where organic acids in the tank chew up alkalinity but since it's not going into coral skeletons in a balanced ratio, you'll have a climbing Ca level until it precipitates out. I'd slowly raise your alk to your ideal level without adding back any Ca.

This article is great about explaining the why and what to fix: https://reefkeeping.com/issues/2004-12/rhf/index.php
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That link clarifies a lot for me.

Also, while kalk is in the ATO for me, my ATO setup uses a doser for delivery so I get a consistent daily spread and amount but then occasionally I'll add RO/DI water by hand to make up any obvious additional loss due to seasonal changes. Still a little manual there...once a week maybe.
 
Prestondeeply said:
@Vincerama2, I've had a similar experience with kalk over the past month. Two tanks are chewing through alk, so I started kalk, which almost stabilized alk, so now I add just a little alk with kalk. But now calcium is rising....near 500 from 430-ish last month. Tank is looking fine, but I don't like the steady rise of Cal over that time...and still needing alk....so they arent consuming the two in equal parts as I had expected.

Is that normal?

On reading the ATO kalk method instructions it also seems to say that we should avoid taking from the bottom 1" of the solution....and I don't think I was doing that.

Any insight is greatly appreciated.

I had been using AFR but noticed the Alk still dropping quickly...so shifted to kalk+Alk. Seems several of us have tanks and their chemistry in just about the same place right now.
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Is your tank primarily soft corals? They will take up alk but not calcium since they don’t have a skeletal structure to build.
 
I second not using kalk in topoff since it will be an inconsistent amount day to day. better to dose a controlled and consistent amount. You can try to match that amount to your consumption.
 
Flagg37 said:
This is also why you want to keep a lid on your kalk reservoir since it will also absorb the co2 from the ambient air. You want to reserve all that co2 absorption for your tank. :)
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I've noticed that as my Kalk reservoir gets low, the pH boost lessens, probably due to co2 absorption from the air. I have mine sealed, but still need a small hole to allow some air in to get kalk out :) I wonder if taller reservoirs with less surface area might work better?
 
Meshmez said:
I second not using kalk in topoff since it will be an inconsistent amount day to day. better to dose a controlled and consistent amount. You can try to match that amount to your consumption.
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Yeah, while not ideal, I think for some, its simply a matter of convenience. You don't need any extra equipment to add Kalk to the ATO... When I used this method years ago, I also recall it being really tough on my ATO pump, haha. I had to clean it constantly.
 
I wonder if some sub saturated level of kalk in ATO could help some with alk and PH but not have much impact based on daily variation.
 
I also don’t recommend kalk in ato, anything I’m adding to my tank I want to be able to control it, evap can’t be controlled so your kalk adding is only added upon evap. If anyone on here wants to discuss kalk please come into the shop, I have a lot of info on kalk dosing, it’s all I use at the shop, I don’t use 2 part or run calcium reactors, I’ve been doing kalk dosing for almost 20 years, and with my new method I adopted a couple years ago tweaking with Chris mecklys method I have found significant results, so please come in and pick my brain! I love talking kalk! My ph never falls below 8.3 I run an average of 8.4, this last week has had a little instability due to not using the air exchange unit it not because it’s so freaking cold out! Usually my average is about 8.45
 
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