Water change matching parameters.

[71xlch]

Quick question. Say you keep your parameters at 8dkh 440ppm cal and 1350mag. You mix up reef crystals which is higher than what you run your tank at(I don't have actual numbers on hand, make up if you need to for the math) What is the calculation used to figured out how much of a swing each parameter will move if you change 10%,15% etc.

Thanks
Kyle.

 

[Randy Holmes-Farley Verified Community Expert]

It is just the weighted average, which for a 10% change, won't be much.

So if the tank has 7 dKH and the salt water 12 dKH, and you change 10%, it is

0.9 x (7 dKH) + 0.1 x (12 dKH) = 7.5 dKH

That clear?

 

[71xlch]

Yes thank you. A lot easier that I thought it would be.

 

[Randy Holmes-Farley Verified Community Expert]

You're welcome.

Only two parameters folks usually measure deviate from this: ORP and pH, which are more complicated.

Happy Reefing