carbonates and temporary hardness

     Hi Folks - 
     Quick question: at the moment I'm using bicarb soda to controll the KH 
     value of my tank water. Is there a compound of potassium and carbonate 
     that would perform the same function? I've looked in the Krib, and an 
     article at 
     refers to muriate of potash as KaHCO3 (sic). I know that muriate of 
     potash is KCl, so this article's probably not right. But I am interested 
     in the potassium / carbonate compound. Could someone expand on this: 
     what it is, and where to get it? 
     Also, to Eng Chuah: re: your post to APD 509 about terestrial fertiliser 
     and potted plants etc - how well do you think this would work with 
     [BTW could someone also tell me what command to give the server to make 
     sure that I get the digests containing my posts? Private e/mail probably 
     Cheers, Chris.