Determining calcium ppm used per day.

[USMA36]

I am dosing escape b ionic 2 part and I am trying to determine my calcium used per day in ppm. If I am dosing 25ml per day into my 100 gallon system what would I be using? it Seems like this should be easy to figure out, but for the life of me I can’t.

 

[Copingwithpods]

Here's what I did, figured out my target parameters, for me it was 9dkh and 450ppm cal. Test water, water tested at 8.5 dkh and 430cal. Use calculator to bring those numbers up to my goal. Now I have a baseline. Wait 24hrs and test again at the same time of day. Let's say dkh drops 0.5 and cal drops 20ppm. Dose those back in allow 24hrs and check again and adjust. By the end of the first week of doing this daily you'll have a great idea of what your tank is consuming on a day to day basis and will help you greatly in dialing it in.

Don't test just after dosing and don't dose both at the same time.

 

[Gareth elliott]

4ppm?

Reef Chemistry Calculator

At least when i put into this calculator. Maybe i am selecting the wrong product

 

[W1ngz]

Daily testing to measure the drop is the better method, but if you want to work it out backwards, try this:

I like this calculator to work out stuff like this. http://reef.diesyst.com/chemcalc/chemcalc.html
Set your system water volume, and select the product you're using. Then play with the current and desired calcium levels until it gives you about what you're dosing. The difference between desired and target is your daily dose in ppm calcium.

 

[W1ngz]

4ppm?

Reef Chemistry Calculator

At least when i put into this calculator. Maybe i am selecting the wrong product

Ha! you beat me to it. That's the same number I came up with.

 

[taricha]

To find Ca consumed per day, you should measure average alkalinity consumed and calculate Ca from that, rather than trying to measure Ca consumption directly.
Why? Because the precision in an alk test is way better relative to daily Alk consumption than the precision in Ca test vs daily Ca consumption.
To be specific, Alk should be repeatable to within 0.1 dkh or better and every day you'll use in the ballpark of 0.5 to 1.0 dKH.
Ca test kit errors are around 20ppm and the daily consumption is much less than that.

Here's the ratio for all calcifying organisms essentially regardless of type -mollusk, stony coral.

or reduced to 1 meq/L:

17.5 mg calcium
1.5 mg magnesium
30 mg = 1 meq/L = 2.8 dKH of alkalinity

sure, some organisms may include slightly more or less Mg in the calcium carbonate they form, but this ratio and alk consumption is way more accurate than trying to measure Ca consumption directly.