Calculating Tank Volume from dosing affect

[pledosophy]

I am trying to calculate my tank volume.

I know that 30mL of Brightwell Aquatics Code B raises my Alkalinity 1.7 dKH on my Hannah meter. Is there a way to do the math backwards to calculate total tank volume so I can use reef calculators and accurately plan other dosing?

 

[pledosophy]

From playing with the calculator I am estimating I am at 53g actual water volume, I just was hoping to learn how to do the math

 

[Ledo]

If
"each ml of Brightwell Aquatics Reef Cōde B will increase the alkalinity in 1 US-gallon (3.785 L) of water by approximately 2.22 dKH (0.79 meq/L)"

and
"adding 30mL in your tank raise it to 1.7..."

So:
- 1mL in 1g raise to 2,22 dKH
- 0,76mL in 1g raise to 1,7 dKH
- 30 mL in 39.5g raise to 1,7 dKH

However, things are not so simple.
This math is probably not 100% accurate.

 

[Jekyl]

Use this

Reef Chemistry Calculator

 

[ca1ore]

It's simply internal dimensions (NOT external) in inches divided by 231. No way to reliably calculate displacement by rock, sand, etc. though.

 

[taricha]

you are way better off measuring dimensions than backfiguring volume from a change in the large uncertainty hanna alk test.
Saying the change in alkalinity is 1.7 dKH +-0.5 is like saying the tank volume is 53 gallons +-16. so between 37 and 69 gallons

The concept isn't crazy though. I just don't know what substance you could dose that would mix quickly, be fairly stable in the water long enough to mix totally thoroughly throughout the system and be able to be measured really precisely.

 

[pledosophy]

you are way better off measuring dimensions than backfiguring volume from a change in the large uncertainty hanna alk test.
Saying the change in alkalinity is 1.7 dKH +-0.5 is like saying the tank volume is 53 gallons +-16. so between 37 and 69 gallons

The concept isn't crazy though. I just don't know what substance you could dose that would mix quickly, be fairly stable in the water long enough to mix totally thoroughly throughout the system and be able to be measured really precisely.

I get what you are saying. I didn't realize the Hanna tests had that much of a swing. I got this one because I was told it is the more accurate of the ones available.

 

[pledosophy]

If
"each ml of Brightwell Aquatics Reef Cōde B will increase the alkalinity in 1 US-gallon (3.785 L) of water by approximately 2.22 dKH (0.79 meq/L)"

and
"adding 30mL in your tank raise it to 1.7..."

So:
- 1mL in 1g raise to 2,22 dKH
- 0,76mL in 1g raise to 1,7 dKH
- 30 mL in 39.5g raise to 1,7 dKH

However, things are not so simple.
This math is probably not 100% accurate.

thank you

 

[blasterman]

It's simply internal dimensions (NOT external) in inches divided by 231. No way to reliably calculate displacement by rock, sand, etc. though.

Just subtract about 15% due to rock and substrate. Less if you are BB and dont have a lot of rock.

 

[elysics]

You could do it via salt/rodi additions and a calibrated hydrometer

 

[Randy Holmes-Farley Verified Community Expert]

I agree that this method for water volume needs materials and methods beyond what the usual hobbyist has to be substantially better than an eyeball estimate.

 

[taricha]

A clever birdie pointed out to me that Mg checks the boxes here fairly well.
It depletes slowly in a system, you can add a lot of it without problems, and titrations for it are quite precise.

 

[Randy Holmes-Farley Verified Community Expert]

and titrations for it are quite precise.

They are?

How do you figure?

 

[taricha]

They are?

How do you figure?

I mean "precise" as in repeatable very similar results. Even if not necessarily accurate.

 

[pledosophy]

I agree that this method for water volume needs materials and methods beyond what the usual hobbyist has to be substantially better than an eyeball estimate.

Thanks Randy, I will abandon this line of thinking then ...... for now.... until we have better tests