Hi all,
I have just checked my local water report in hope of gaining some insight in to how my local water perimeters effect my tank and EI fertilisation, after looking at all the figures I feel a bit bewildered.
Looks like a lot of the water from S & E of the UK, conductivity 600microS ish, probably mainly calcium Ca2+ ions, as pH7.8 is where strongly carbonate buffered water ends up. To get to a "dKH" value from "Total Hardness as CaCO3 mg/l = 263", you need to divide 283/16.7 = 17dKH.
A fair amount of nitrates - 25ppm, and some ammonium - NH4+ 0.12ppm, also mention of "residual disinfectant", so probably disinfected with chloramine. Everything else fairly low.
As Clive says, fine for the planted tank, but probably not for keeping soft-water fish in (too hard), or if you kept Mbuna in a non-planted tank, where you would need to reduce the initial NH3/NO3 levels. That is one of the great advantages of growing plants, they will reduce NH3/NO2/NO3 levels very efficiently.
You could reduce the amount of NO3 you add (the range of NO3 values through-out the years is low = 22ppm - 31ppm, suggesting domestic sewage as their source, rather than agriculture), but if you don't use KNO3 you will need an alternative potassium source (KCl etc.).
I've never tried EI, but Clive says you can add as much NO3 as you like without any problem, so I would probably use the EI dosing scheme as is.
cheers Darrel