"Pszemol" wrote in message
...
"George" wrote in message
news:d0Z8e.409$WI3.145@attbi_s71...
I would add buffers at this point, before you add the expensive salt.
RO water is depleted of minerals and will take them up like a sponge,
potentially leaving you with a lower than desired pH. Best to add either
baking soda or a commercial buffer like the Seachem product.

And what if you overdose buffers? Will you add *less* of "expensive salt"?
What if your baking soda will replace to much of other essencial ions
since you measure total salnity INCLUDING previously added baking soda
in place of salt mix ?

This comment about the sponge sounds very amusing. Salt mixes are designed
to use them with pure water. Manufacturers do not count on minerals in
tap water to mix to the right levels... If you add too much buffer to ro
water before mixing salt you might overdose buffers/alkalinity and the
whole
batch of brine will not mix well or will be way off the chart...

Again - reinventing the wheel! Please quote a single salt manufacturers
mixing instructions advocating adding buffers first and then mixing
salt...

Actually there are some salt mixes that are designed to be
used with regular tap water. (This taken from Anthony
Calfo's book on coral propagation.)