Kalk dosing help please

scrappy35

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I have been dosing kalk for a couple months now and I am having a problem with high calcium and low alk. Currently I am at 470 calcium and 6.2 alk. I am using reef crystals salt at 1.026. Corals are growing, but I am struggling to maintain alk. I started dosing kalk based on my alk uptake. Ph runs 8.35 day down to 8.2+ at night. I primarily dose at night. I have an x1 with 12 times(1.5 hrs apart) dosing 112 ml of kalk each dose into my the return chamber of sump. Tank is 120g + 40b sump, I’m using 150g for my calculations. Current plan is to reduce my kalk a small amount and use Randy’s part 1 to dose alk back to 8.5 over the next couple of days.

what would cause calcium to be high and alk to drop every time I dose it back up?

on a side note note, I can now see the relationship between co2 in the house and ph. Every time we go camping (2 adults and 4 dogs) I get alerts that my ph is greater than 8.4. When everyone is back home it stays around 8.35 peak.

thanks
shane
 
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Randy Holmes-Farley

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Kalkwasser is slightly overloaded with calcium relative to alk for long term dosing. I got around that by using a low calcuim mix (normal IO) for routine water changes, but you can also get around it by occasionally boosting the alk with baking soda or sodium carbonate.
 
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scrappy35

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That’s the answer I was looking for. I already have a batch of your #1 mixed. I will dose kalc for calcium and then supplement alk with another doser. Sitting on too much reef crystals to change now.
 
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That’s the answer I was looking for. I already have a batch of your #1 mixed. I will dose kalc for calcium and then supplement alk with another doser. Sitting on too much reef crystals to change now.
Not so fast...

Reef Crystals:
SmartSelect_20220706-025558_Chrome.jpg


Now assuming your measurements are accurate...a drop of 13dKH to roughly 6.2 would expect a drop of about 48ppm Ca.

Most Ca measurements are +/- 10% in my opinion and dKH measurements +/- 0.5. So that drop in Ca relative to dKH is probably in the error range of your measurements.

So another possibility is you are under dosing and your tank is just depleting Ca/Alk as expected.

How are you dosing Kalkwasser? And how much are you dosing?

To see the Ca/Alk imbalance from long-term balanced dosing takes takes several weeks to several months depending on your tank's livestock specific consumption.
 
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scrappy35

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I am dosing kalkwasser 12 times a day, mostly overnight, at 185mls at a time. I have 150g total volume and do 15g changes a week. I have been struggling to keep my alk up, but calcium no more than 450.
 

arking_mark

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I am dosing kalkwasser 12 times a day, mostly overnight, at 185mls at a time. I have 150g total volume and do 15g changes a week. I have been struggling to keep my alk up, but calcium no more than 450.

So that's a pretty low dose. You're only dosing roughly 0.3dKH per day.
 
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scrappy35

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At the time I started, that was my calculated usage. My usage has gone up, but it was the calcium levels that had me concerned. I would gladly go up, but at what point should I just add alk over kalkwasser? At some point I can switch salts, but I am sitting on 2- buckets and 3 boxes from when it went on sale.
My plan is to dose alk back up and recalculate usage now that corals are growing pretty well.
What are the adverse effects of high calcium?
 

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At the time I started, that was my calculated usage. My usage has gone up, but it was the calcium levels that had me concerned. I would gladly go up, but at what point should I just add alk over kalkwasser? At some point I can switch salts, but I am sitting on 2- buckets and 3 boxes from when it went on sale.
My plan is to dose alk back up and recalculate usage now that corals are growing pretty well.
What are the adverse effects of high calcium?

I'm not really seeing an imbalance issue here, just a maintenance/stability issue.

You are using a high Alk/Ca salt mix and your replacement dosing with Kalkwasser and water changes with said mix aren't keeping up with consumption and/or your target levels.
 
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scrappy35

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Ok, if I got this straight: my calcium dosing is fine with the salt I’m using, but alk is not. I can continue with my normal routine and just supplement a little extra alk to the system. I can’t add more kalk due to its high calcium content. I’m only using kalk over 2 part to keep my ph up and more stable. I get about a .1 swing from day to night and average 8.3. I don’t want to change salts since I have so much on hand. i have a second dosing pump so I can supplement alk with Randy’s recipe #1. This way I can keep both alk and calcium stable without running one or the other too high.
 

Randy Holmes-Farley

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Ok, if I got this straight: my calcium dosing is fine with the salt I’m using, but alk is not. I can continue with my normal routine and just supplement a little extra alk to the system. I can’t add more kalk due to its high calcium content. I’m only using kalk over 2 part to keep my ph up and more stable. I get about a .1 swing from day to night and average 8.3. I don’t want to change salts since I have so much on hand. i have a second dosing pump so I can supplement alk with Randy’s recipe #1. This way I can keep both alk and calcium stable without running one or the other too high.

Yes, that sounds fine.
 
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