Alkalinity good, but Calcium way high

[Waterbourn]

I have been using Reef Fusion 1 and 2. I had it worked out and am adding about 5 caps a day. After a while I just went to measuring alkalinity. Lesson learned. I measure alk almost daily and keep it around 3 meq/L. On a whim i decided to measure calcium and it was way over 600. So alk has been good, but i think that is too high for the calcium. Everything seems to be doing good though except some of my zoas.

Can i just dose alk for a while? Any other thoughts and help?

Thanks.

 

[Randy Holmes-Farley Verified Community Expert]

I suspect some issue other than just simple overdose. Maybe even test error. Try the kit on some new salt water.

 

[Randy Holmes-Farley Verified Community Expert]

Yes, if you are convinced the calcium is really high (doesn’t seem that likely to me, but it could be) then dosing just alk in some way is fine.

 

[Waterbourn]

Thanks. So i retested and yesterday after replicating the API tests I needed 29 drops for calcium which is 580. Today I added my usual 5 caps of fusion for just alk and brought it up to 3.0 meq/l. A calcium test afterwards took only 28 drops so it went down a little to 560. Still really high. I will just keep this routine until i get it in range.

I thought 2 parts that were added at the same amounts kept the two parameters in line. It surely didn't do that for me. I will be more careful in the future with these 2 parts for sure.

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, API kits do not have the best reputation.

 

[Randy Holmes-Farley Verified Community Expert]

Try the kit on some new salt water.

 

[Randy Holmes-Farley Verified Community Expert]

Edit: I need to double check the design of this product tomorrow to see if it is correctly designed to be 1:1 dosing

 

[Randy Holmes-Farley Verified Community Expert]

Actually now that I look closely at Seachem Reef Fusion, it appears to be incorrectly designed to have excessive calcium, despite claiming to be a 1:1 additive.

The calcium is 100,000 ppm (100 g/kg) calcium. Even ignoring the density being higher than 1, that means a liter contains 100 grams or 2.5 moles of calcium. In reality, it will be even higher due to the density being higher than 1 g/mL.

They claim the alk part contains 4400 meq/L. So one liter contains 4400 meq or 4.4 equivalents of alkalinity.

4.4 equivalents of alk will combine with 2.2 equivalents of calcium to make totally pure calcium carbonate, or a bit less than 2.2 equivalents of calcium since magnesium and strontium swap into the crystal in place of calcium.

But the product adds more than 2.5 equivalents, not a bit less than 2.2.

Even accounting for issues such as the salinity rise over time, this product looks to have too much calcium to be 1:1.

This, I conclude Reef Fusion is not properly designed for 1:1 dosing,