Is this right?

[blkhawk10]

I just tested my tank and have found out that I have low calcium levels at 375 ppm and I wanted to raise them thru a 2 part doser up to 420 ppm...I went on the BRS calculator and it tells me that I should dose 253.3 ml to raise up calcium to the desired level. Should I dose the same amount of alkalinity per day cause it seems pretty high?

 

[Randy Holmes-Farley Verified Community Expert]

NO, definitely do not dose an equal amount of the alkalinity. That would send alk way too high.

Equal parts dosing only applies to what is being consumed by calcifying corals and such, not to making significant corrections to calcium levels, which may be driven largely by the salt mix.

 

[blkhawk10]

How do I figure out how much to dose then? I'm all new to this.

 

[aaron23]

did you get the right units? I left it on something other than dkh before and i said WHAT this much to raise it up? then realized it was in the wrong units.

 

[dbrewsky]

its pretty common to need a large dose of calcium to raise levels ~50ppm. What is your tank volume? perhaps we can confirm these numbers for you.

 

[blkhawk10]

55 gallons i'd say total water volume.

 

[dbrewsky]

that does appear to be the correct amount to raise your calcium ~50ppm. you can always break that dose up over two days and test between to ensure you don't overshoot your calculations. Calcium is easier to adjust since it wont shoot your ph up by adding it, however with any supplement ensure you can test and monitor how much you are adding.

 

[Randy Holmes-Farley Verified Community Expert]

How do I figure out how much to dose then? I'm all new to this.

You are doing it right. But you are only raising calcium now so dose only that.

If alkalinity declines below where you want it, then dose equal parts of calcium and alkalinity to maintain the alk where you want it (based on a calculated dose) and the calcium will follow along OK.

 

[JimWelsh]

Yes, your 253.3 ml of Randy's Recipe #1 Calcium Part is correct to raise the Ca in 55 gallons from 375 to 420 PPM.

 

[dbrewsky]

I wanted to raise them thru a 2 part doser up to 420 ppm

So even with having 2-part dosers to automate adding calcium and alkalinity, you will at times need to do corrections based on testing to bring some parameters back into range, just like with your calcium right now.

It is best to do these manually and in your case add the 253.3 ml of calcium to bring you back to your target. If it continues to drop over the next couple weeks, then you might need to adjust your doser settings to reflect the your aquariums actual demand.