Right. But your statement is not always true. And I think it is more often wrong than right for the reasons I gave. It certainly may be why they chose a lower concentration, but that doesn't make it correct. That said, a lower concentration is also fine if folks want to use it for any of several reasons. More valid reasons, IMO, may have to do with less potential for local precipitation of calcium carbonate when the alk part hits the water. And, of course, having the dose be delivered properly by a dosing pump you already have might be optimiized by a particular concentration that may be more dilute than normal.
I've seen them too. And that is exactly what I think may be causing more angst and wasted money and effort in the reef community than it is worth. If you look close enough, any real water sample will have most ions in it. So how much is too much? How much silicate in RO/DI is too much? Phosphate? Is 0.05 pm phosphate in your RO/DI top off too much? Many would immediately think yes, when in reality it is a trivial contribution to the tank phosphate cycle. FOr silicate, there may be no reasonable amount that is too much unless you have a diatom "problem".
IMO, there is no useful guidance being given in some of the RO water reports, and folks often leap to very incorrect conclusions about what those values mean.
