MINIATUS said:One more question on this mix. I was just looking at a small container of Kent Marine pH buffer and it mentions borate salts. What are they and where does this fit into the mixture.
MINIATUS :?:
Borate is frequently added to commercial Alk boosters. It will contribute to total alk, but is not used much by marine animals. Borate is added to buffer more effectively in the 8.1-8.4 range when mixed with carbonate/bi-carbonate buffer systems. In natural sea water Borate is very small in concentration to carbonates but contributes very largely to total alk because of its strength as a buffer. Carbonate/Bicarbonate buffers by themselves do not exhibit the correct pKa to provide the strongest buffering power in the range we need them. Adding borate to the mixture adjusts the sweet spot of maximum buffering to the 8.1-8.4 range if added in the correct proportion.
I am not an advocate of borate based buffering systems, other than the borate naturally present in the salt via WC's. If you add an alk booster containing borate, because it is not used by corals at the same rate (much slower if at all) than carbonate/bi-carbonate, it will gradually become a dominate factor in your total alk, which you don't want. This is because the carbonate is constantly consumed but the borate isn't. Several commercial 2-part additives do not contain borate. I would suggest one of them, or stick with the homeade baking soda/washing soda mixture, which I believe is best. Just let WC's give you the borate and that will keep your tanks ratio of Borate to Carb/bicarb where it should be and then just add BS/WS to maintain between WC's...Collin