An easy way to oversalt
Diamond Crystal → table salt
That teaspoon jumps from about 2.83 g to 5.88 g. You’ve added more than twice the salt the recipe intended.
Translate the salt in your recipe to the salt in your kitchen.
Decimals or fractions, such as 0.5 or 1 ½.
On a kitchen scale
Volume compared to recipe

Fine grains pack tightly. Larger, airy flakes leave more space between crystals. So a spoonful of one salt can contain twice as much salt as another.
One reliable common measure
For these cooking salts, weighing out the recipe’s grams gives you a much closer match, whatever the crystal size. 10 g of table salt and 10 g of Diamond Crystal deliver essentially the same amount of salt once dissolved.
If your recipe gives a weight, use it. If it gives teaspoons or tablespoons, match the named salt or convert it here. A scale that can resolve small amounts helps; measuring spoons are still useful for everyday cooking.
Finishing salts are a little different: crystal size also changes the crunch and how salt hits your tongue.
“Measuring things like salt or flour by volume is remarkably inconsistent.”