What it the normal range of PH, KH and GH swings?

[Sf1]

When I do water change (20-25%), PH stay always at 8.0.
But KH or GH can rise.
KH from 6 to 7.
GH from 161.1 to 179.

Maybe it's just a testing error.
But if it's true, how harmful those swings can be?

Thanks

 

[Fishguy1111]

When I do water change (20-25%), PH stay always at 8.0.
But KH or GH can rise.
KH from 6 to 7.
GH from 161.1 to 179.

Maybe it's just a testing error.
But if it's true, how harmful those swings can be?

Thanks

That seems high for gh. Kh I'm not certain about so I won't say, although that's high for gh. Ph matters on what fish, although 7 is considered neutral, it matters what fish you have. The conditions not changing is probably due to your tap water parameters.

Hope that helped

 

[mrvincent]

He's probably telling his GH is 160-180 ppm so probably 8-10 dGH°.

The GH should not swing with WC, it's probably a testing error, but anyway it won't harm.

If KH change suddently, (like if you add big shot of baking soda), it can make a big change on the PH, and THAT'S HARMFULL.

 

[Fishguy1111]

He's probably telling his GH is 160-180 ppm so probably 8-10 dGH°.

The GH should not swing with WC, it's probably a testing error, but anyway it won't harm.

If KH change suddently, (like if you add big shot of baking soda), it can make a big change on the PH, and THAT'S HARMFULL.

That would make more sense. I'm just used to dGH'