Kent users: alk/precipitation in new SW?

[Delphinus]

After using IO for the longest time, I just switched to Kent salt a few months ago.

I get terrible precipitate out of a new batch of saltwater. Is this fairly common?

Here's how I mix my SW:
- fill 30g bucket with RO
- heater and a 802 powerhead for about 24 hours to get up to tank temp
- mix in salt
- I use a drill mixer and run the drill for a few minutes
- let sit (with heater and powerhead) a couple more days before using.

After I come back to it after about 24 hours, there is a serious calcium precipitate over everything. The heater is coated, the powerhead is coated, and the green rubbermaid container is literally white on the inside.

I switched to Kent because it I heard it mixes with a higher alk out of the box than IO. I haven't tested the alk of a fresh batch yet but it must be pretty high to rip out calcium in this quantity.

Is there something I could improve upon my methods? Could I have a bad batch of Kent? (I'll test alk of a fresh batch next time I mix some and will have a better idea at that time.) But I'd really like to hear opinions and experiences of other Kent users in the meantime.

The other theory I have is that there's something amiss with my RO water. It's not RO/DI, it's just RO and my membrane is probably a few years old. All I have tested the water for is PO4 and NO3 and of course those are zero readings. But I have no idea about TDS or any other parameter.

Thanks!