Help with math

[BlackTip]

I am so embarrassed to even post this question. But, here it is: My DT S.G. is 1.0264. I want to bring it down to 1.025. I mix 50g at a time, so I am going to replace 50g.

I put this formula together. I plugged in some numbers, and it seems to work.
I'd like someone with math skills to double check it, and solve it for Y. It has been so long, since I used mathematical formulas.

X - DT S.G.
Y - S.G. of replacement water
R - amount of water to be replaced
G - total water volume
F - final S.G. in the DT

X - ( ((X-Y)/X) * (R/G) ) = F

Is the above formula correct?
Could someone solve it for Y instead of F?

Thanks,

 

[Shawn O]

https://www.hamzasreef.com/Contents/Calculators/DirectSaltCalculator.php

 

[BlackTip]

Thanks Shawn, I found the calculator. I still would like someone to solve the formula for Y. I'd like to keep it handy.

 

[KafudaFish]

I do enough 6th grade math so I would just mix the 50 gal to the correct salinity and do one gallon wc once every few days and let my ato adjust it further.

 

[Wazzel]

Y=x-((Gx(x-F))/R)

 

[Wazzel]

I do enough 6th grade math so I would just mix the 50 gal to the correct salinity and do one gallon wc once every few days and let my ato adjust it further.

I would (and have) pull out a volume of water a few times a day and let the fresh water top off do the rest. Checking the SG before pulling out the next bit of water, of course.

 

[Adam15]

Wow that hurt my head

 

[BlackTip]

Y=x-((Gx(x-F))/R)

Thanks Mark

 

[Wazzel]

No problem, not sure if the initial equation is correct. I did not look into it.

 

[Dkuhlmann]

No, Really. It's not that complicated, no really it isn't!

 

[Wazzel]

No, Really. It's not that complicated, no really it isn't!

I'm an engineer and part time math tutor for my kids and their friends. It really is not that hard for me. This year is mostly algebra II and pre-calculus with some grade school math thrown in from my son.

 

[billdogg]

Thanks Shawn, I found the calculator. I still would like someone to solve the formula for Y. I'd like to keep it handy.

No problem

Y = a dollar three fidy

hth

and fwiw - I'm in the just take some out, add fresh ro/di, repeat

 

[Roccus]

Wow that hurt my head

mine too.... count me in the take a little out...put A little in club..

 

[stingeragent]

mine too.... count me in the take a little out...put A little in club..

My head also hurts just looking at this. I use a calculator for 10 x 10. (not really that bad but you get the idea)

 

[Dkuhlmann]

I'm an engineer and part time math tutor for my kids and their friends. It really is not that hard for me. This year is mostly algebra II and pre-calculus with some grade school math thrown in from my son.

I figured it was something like that. Only an engineer or a math teacher would have asked the op. :beer: