Anyone care to check my math....?

RandoReefer · Sep 30, 2014

I would like to free up a dosing pump that is currently dosing Vinegar. I was thinking about the vinegar to my ATO reservoir to dose. My math thought process follows:

Known:
-Currently dosing ~17.6mL/day

-ATO Reservoir= 30gal

-1gal of vinegar = 3785.41mL

Ok... here are my approximations:

-Adding 1gal of vinegar to 29gal dilutes it to 130.53mL/29gal..... (29gal because vinegar will take up the extra gallon of volume in ATO)

-ATO uses approx 2.14-gal/day (I refill roughly every 2-weeks... (30gal / 14days))

-Using these values I assume that I would dose approx 55.31mL/day of diluted vinegar.... (130.53mL/30gal divided by 2.14gal/day = 55.31mL vinegar/day)

-Finally, using the value of 55.31mL vinegar (and using the same math) I can deduce that by half-ing the gallon of vinegar, I should be dosing approx 22.65mL/day

Please let me know if I'm WAY off..... and if I'm close, would dosing vinegar this way be a worthwhile? Or should I just invest in another dosing pump?

redfishbluefish · Sep 30, 2014

If you add one gallon of vinegar to 29 gallons of water you have a "vinegar" concentration of 3785/30 = 126 mls of vinegar per gallon.

If you dose 2.14 gallons per day, you are putting in: 126 x 2.14 = 270 mls of vinegar per day.

So if you wish to dose approximately 17.6 mls of vinegar per day from your ATO (and using your approximations) you need to put 247 mls of vinegar up to 30 gallons of ATO water.

Oh, and here's the math on that:

247 mls vinegar / 30 gallons X 2.14 gallons / day = 17.6 mls vinegar /day

RandoReefer · Sep 30, 2014

Yep, I had an inkling that my last calculation was multiplication instead. Well, let the experimentation begin...!

Thank you!

Randy Holmes-Farley · Oct 1, 2014

Is there limewater is this ATO?

If not, I'd be concerned that having diluted vinegar in it will lead to excessive bacterial growth and consumption of the vinegar in the reservoir.

Full strength vinegar can't grow bacteria due to the very low pH and possibly for other reasons, but diluted vinegar can.

RandoReefer · Oct 1, 2014

Randy Holmes-Farley said:
Is there limewater is this ATO?

If not, I'd be concerned that having diluted vinegar in it will lead to excessive bacterial growth and consumption of the vinegar in the reservoir.

Full strength vinegar can't grow bacteria due to the very low pH and possibly for other reasons, but diluted vinegar can.

It does not, as I dose 2-part. Hmmmm...

You can't add vinegar to Sodium Carbonate or Calcium Chloride solution, correct?

Randy Holmes-Farley · Oct 1, 2014

Yes, you can add it to the calcium solution.

RandoReefer · Oct 1, 2014

Well now, that makes my situation much easier. Not to mention more controllable and accurate.

Thank you!!!!!

RandoReefer · Oct 1, 2014

Ok, now this has the math wheels turning in my brain.

-1gal of calcium solution is 3785.41mL.

-I want to dose 66mL of calcium solution per day.

-What ratio of vinegar to calcium solution do I mix to achieve a daily dosage of 17.6mL of vinegar and 66mL calcium solution?

I bet the answer is staring me in the face... I'm a math wiz in training, still.

redfishbluefish · Oct 1, 2014

Since you already have your calc solution made (at 3785 mls) you will want to add 1009 mls of vinegar to this, for a total volume of 4794 (assuming no close order packing or any of that nonsense). But now you will have to dose (66 + 17.6), 83.6 mls to get an effective dose of 66 mls of calc and 17.6 mls of vinegar.

EDIT TO ADD:

Here is how I came up with these numbers. At 66 mls per day of calc dosing, a 1 gallon container (3785 mls) equals (3785/66) 57 doses. 57 doses of vinegar at 17.6 per day equals (57 X 17.6) 1009 mls of vinegar. Add the two total volumes together (3785 + 1009) for a total volume of 4794 mls....and now add the two dosing volumes together (66 + 17.6) for a total dose of 83.6 mls.

Randy Holmes-Farley · Oct 1, 2014

Don't dilute it more than that. It might even be better next time you make it up, to make the vinegar be part of the 1 gallon of liquid. Then you can dose what you are now, and the pH and saltiness should keep anything from growing.

RandoReefer · Oct 1, 2014

I did come up with the 83.6mL based on the same calculation.

Please forgive my misunderstanding of the ratio/proportion, but would I still use 1009mL-vinegar to make the final solution or would that be scaled down to account for the total 3785mL of volume?

I see that it is close to a 3:1 ratio, but as Randy has alluded to, I am using a 1gal container.

I hope that makes sense. Thank you very much for your help Gents!!

Randy Holmes-Farley · Oct 2, 2014

Depends on how you make up the solution. If you make it by mixing 1 gallon calcium solution and then add vinegar, do it the way redfish described it exactly.

If you add the 1009 mL of vinegar into a 1 gallon container, add the usual amount of dry calcium and then add water till its full, you dose the same amount you always did (66 mL).

What you did in the latter case was swap some of the water for vinegar, but the total dose stays the same.