Folks after 4+ decades of using little test tubes I finally broke down and bought some Tetra 5-in-1 EasyStrips to speed up the casual water tests. Normally I only test nitrates. Water, and buffers fix everything else.
Everything was OK, and I tested my tap water and 6 tanks. But the brackish tank gave goofy results.
I was changing the water and mixing up Instant Ocean in a bucket before I saw the error.

The pack is labeled "for freshwater or saltwater", but the bottle inside says it is for freshwater.
I thought maybe someone switched bottles in the store, but I only saw one type on the shelf.
The API tests were conclusive. These strips don't work with salt.
Everything was OK, and I tested my tap water and 6 tanks. But the brackish tank gave goofy results.
I was changing the water and mixing up Instant Ocean in a bucket before I saw the error.

The pack is labeled "for freshwater or saltwater", but the bottle inside says it is for freshwater.
I thought maybe someone switched bottles in the store, but I only saw one type on the shelf.
The API tests were conclusive. These strips don't work with salt.