Does anyone know of a reliable recipe for a malawian salt mix? I need this for a commercial scale system, so the otherwise commercial additives are too expensive. The water here is very soft and somewhat acidic--1-2 dKH, 3GH, pH 6.7 all out of the tap. I assume I will need something along the lines of sodium bicarbonate, magnesium sulfate, calcium chloride (or sulfate, but there is a much smaller Ca ratio, anyway, so would the added Cl- be a problem?). Some suggest potassium chloride and sodium chloride, but the general consensus here is to generally omit them, though they seem to be major players in supposed analyses. What if I used a small amount of sea salt (which we do have cheap) to satisfy the latter two? If not, any recommendations on ratios per gallon, etc? Oh, and it seems that our substrates only buffer long enough until they get a biofilm on them, then they lose a lot of their 'umph', hence the need to help it out.
TIA,
Andrew
TIA,
Andrew