Susan- There is a good discussion of rift lake salts on The Krib at http://www.thekrib.com/Plants/CO2/rift.html For lake Malawi cichlids I like to use marine salt mix. It is not the same as rift lake salt but is a good mix of salts and I can go out and buy it easily (always having a consistent chemical makeup). The amount is a matter of personal preference. I use about a teaspoon for every five gallons, which is not very much. At that rate the expense is low enough for me, and the fish seem to like it. For Lake Tanganyika cichlids I add a teaspoon of Epsom Salts and one of baking soda in addition to the teaspoon of Marine Salt. Ther are many different opinions on this. Steev ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe gsas-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/gsas-member/