OK Guys and Gals,
Here it is.
Basically you get Class I and Class II specs for water. I am going to give the class I specs (class II in brackets).
According to the SANS 241 std., water can be passed at Class II for human consumption for short periods. They do strive to meet Class I specs consistently though.
results in ppm (except pH )
Dissolved solids (TDS) - <1000 (1000-2400ppm)
pH 5.0-10.0 (4.0-10.0)
Ammonia (as N) <1.0 (1.0-2.0)
Nitrate and nitrite (as N) <10 (10-20)
Calcium as Ca <200 (200-600)
Fluoride (F) < 1.0 (1.0-1.5)
Magnesium <70 (70-100)
Potassium <50 (50-100)
Sodium <200 (200-400)
Sulphate <400 (400-600)
Zinc <5 (5-10)
The rest are in parts per billion
Aluminium <300 (300-500)
Sb (Antimony) <10 (10-50)
Arsenic <10 (10-50)
Cadmium <5 (5-10)
Chromium <100 (100-150)
Cobalt <500 (500-1000)
Copper <1000 (1000-2000)
Cyanide <50 (50-70)
Iron <200 (200-2000)
Lead <20 (20-50)
Manganese <100 (100-1000)
Mercury <1 (1-5)
Nickel <150 (150-350)
Selenium <20 (20-50)
Vanadium <200 (200-500)
DOC (ppm) <10 (10-20)
No specification for phosphates is in the std
So there are some not so nice values there which would be quite problematic. Actual results would vary from municipality to municipality depending on source water.
I did get some actual results previously from ERWAT (East Rand) which were pretty good (way at bottom of Class I specs), but these cannot always be guaranteed as the std does allow for much higher values.
So basically do not use tap water for your marine tank.
Personally though if I really needed to I would use a small amount (not more than around 5%-10%) of system volume if I was really in a pickle and could not get any RO. But this is in extreme circumstances only and once-off, not for weekly top-ups or water changes
Here it is.
Basically you get Class I and Class II specs for water. I am going to give the class I specs (class II in brackets).
According to the SANS 241 std., water can be passed at Class II for human consumption for short periods. They do strive to meet Class I specs consistently though.
results in ppm (except pH )
Dissolved solids (TDS) - <1000 (1000-2400ppm)
pH 5.0-10.0 (4.0-10.0)
Ammonia (as N) <1.0 (1.0-2.0)
Nitrate and nitrite (as N) <10 (10-20)
Calcium as Ca <200 (200-600)
Fluoride (F) < 1.0 (1.0-1.5)
Magnesium <70 (70-100)
Potassium <50 (50-100)
Sodium <200 (200-400)
Sulphate <400 (400-600)
Zinc <5 (5-10)
The rest are in parts per billion
Aluminium <300 (300-500)
Sb (Antimony) <10 (10-50)
Arsenic <10 (10-50)
Cadmium <5 (5-10)
Chromium <100 (100-150)
Cobalt <500 (500-1000)
Copper <1000 (1000-2000)
Cyanide <50 (50-70)
Iron <200 (200-2000)
Lead <20 (20-50)
Manganese <100 (100-1000)
Mercury <1 (1-5)
Nickel <150 (150-350)
Selenium <20 (20-50)
Vanadium <200 (200-500)
DOC (ppm) <10 (10-20)
No specification for phosphates is in the std
So there are some not so nice values there which would be quite problematic. Actual results would vary from municipality to municipality depending on source water.
I did get some actual results previously from ERWAT (East Rand) which were pretty good (way at bottom of Class I specs), but these cannot always be guaranteed as the std does allow for much higher values.
So basically do not use tap water for your marine tank.
Personally though if I really needed to I would use a small amount (not more than around 5%-10%) of system volume if I was really in a pickle and could not get any RO. But this is in extreme circumstances only and once-off, not for weekly top-ups or water changes