Baking soda = bad?

[asylumdown]

Thanks guys. I'm totally at a loss for what's happening. Two of the colonies that are dying are ones that I've had the longest and have always done well. The only other thing I can think of is that my strontium levels are really low, I just tested and there doesn't appear to be any strontium in the water. I'll try lowering the dKH over the next few days and see if that helps anything