Stability

[Mules1]

Everyone talks about stable perameters. For the most part mine are stable at Alk 8, Ca 440, mag 1290 - 1300.

Then comes the water change - tested at Alk 11.5, Ca 520, Mag 1500.

Does the swing of a 25-30% water change have negative effects?

Should I be doing smaller water changes?

OR
Don't worry about it and just make stable between changes?

 

[NastyZ]

I wouldn't worry about it just make sure they r stable after that's the reason most people do water changes so they don't have to does the water change replenishes alk cal mag along other things

 

[KCombs]

....Naw, 25% H2O changes ain't nuthing to fret over.... I've read here on RC about people going through all this hub-bub with "temperature adjusted mixing stations" and letting the water age and all this-n-that, but IME the concern/fuss is unfounded : for SW a 33% change might be pushing it but anything under 25% is safe so long as the water is at room temp and the AFSW is mixed until fully dissolved (its clear)....

IME alkalinity is the only param my corals seem particularly sensitive to....and if there was any test I won't skip, its that .... I must spend a small fortune on those pricey Hanna packets
after that would be temperature...

everything else seems to be tolerated in so far as "reasonable" swings/changes are concerned

 

[bertoni]

I personally would keep the water changes limited to 10-15% or so except in emergencies. That said, regular large water changes can be fine, depending on the water source and how the tank is treated.