I stopped rolling my buckets long ago and had consistent enough NSW readings
I bought 2 buckets back in July with matching batch #s
I opened one in Aug and the first 2 batches of NSW gave me;
9.6
385
1260
I could deal with the low Ca and Mag by dosing my NSW, and I'd deal with the Alk boost by turning my doser off for a day or two
I made a batch a couple days ago from the second bucket;
14.4
490
1185
It's the alk swing I'm upset about
I re-tested, used reference tests, used new Salifert kits, checked my refractometer calibration ...
How in the world am I supposed to keep my tank semi-stable when a 15% WC will take my tank from for example;
7.3
430
1380
To;
8.4
439
1350
Just last week I finished building a stand for a larger NSW tank and will be performing 25% WCs bi-monthly very soon
Look what'll happen after a 25% WC
From;
7.3
430
1380
To;
9.08
445
1331
Imagine the instant pH boost I'll get and how upset my corals will be
You can bet I'll be rolling the bucket this week to see if it helps at all