OK, I sent Oceanic the water parameters and asked for a refund. I got this response:
"Thank you for your email, and your interest in Oceanic products. At a specific gravity of 1.021 – 1.023 Oceanic sea salt yields calcium concentrations of 420 – 480
ppm which are comparable to natural sea water. While some reef tank aquarist's prefer to maintain their tanks at a specific gravity of 1.025 or greater, this high specific gravity with Oceanic Sea Salt results in calcium levels that can exceed 550
ppm that can disturb the delicate carbonate/bicarbonate equilibrium causing pH fluctuations. For a reef tank, we recommend Oceanic salt be used at 1.024 specific gravity, which should yield high calcium and magnesium levels without causing hardness and pH imbalance. Here are some suggestions from our scientist who formulated our salt for aquarist who feel it is necessary to run their tanks at a higher specific gravity.
1) Mix Oceanic salt to
sg 1.023. to this slowly add and completely dissolve solid analytical reagent grade sodium chloride to desired
sg. This procedure will increase
sg without effecting calcium and magnesium levels.
2) Mix Oceanic salt to
sg 1.023 – 1.025. Before adding to tank, treat with dKh hardness buffer to attain dKh of 5-7. Add gradually to tank after solution has equilibrated. If I can be of further assistance, please let me know. "