INSTANT OCEAN SALT

[farmerjo90]

I just found an old bucket of salt in my garage. It is unopened but dates back to the day when the buckets made 200 gallons and you got the free plastic plants. I opened the sealed bucket and the salt looks just like new. No lumps at all. So, I mixed up a gallon and tested it. I just have 3 kits. The calcium and magnesium are fine. The alkilinity is double what it should be. I tried it 5 times. The test works in my tank water fine and in the test solution that comes with the kit. I am scratching my head. Any ideas?