Measuring input/output flow for water changes?

[It’s the Grim Reefer]

Hey Reef Keepers,

Wondering does anyone accurately measure their output and input when they do a water change?

I’m thinking about connecting a flow meter of sorts to my plumbing so I can pull out say 38 litres and replace it with the exact same amount. I always estimate it and while I’m sure I’m always close, even if I’m half a litre off, the ATO might make up the difference and then slightly alter my salinity.

Curious to see what others have setup to increase their accuracy with water change volumes?

 

[Science/G]

I have just made estimations, then adjustments depending on my sump level.

 

[gbroadbridge]

Hey Reef Keepers,

Wondering does anyone accurately measure their output and input when they do a water change?

I’m thinking about connecting a flow meter of sorts to my plumbing so I can pull out say 38 litres and replace it with the exact same amount. I always estimate it and while I’m sure I’m always close, even if I’m half a litre off, the ATO might make up the difference and then slightly alter my salinity.

Curious to see what others have setup to increase their accuracy with water change volumes?

2 x 5 gal buckets out, 2 x 5 gal buckets in.

Any difference is fixed by the ATO. It's not that critical on a 10% water change.

 

[braaap]

Not an emergency.

 

[KStatefan]

Pull out what I want then fill back to the normal level.