So all my parameters as of now are:
Ammonia / Nitrite: 0
Nitrate: 5ppm
Phosphate: 0.5ppm
Calcium: 340ppm
Magnesium: 1100ppm
dKH: 10
Salinity: 0.0025
Temperature: 26-28oC
I lost the reference card for my pH test (ack!) but it looks the same colour as always 8.2 so I guess I need another one of those now (more money

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So would I be right in thinking I should be doing the following:
Calcium: Work on getting that up to around 450ppm (I am using Kent A & B)
Nitrate: Cut back on the feeding and see if I can get that back down to zero.
Phosphate: Keep running Rowaphos and doing water changes to get that as close to zero as possible.
Magnesium: Should I bother trying to raise from 1100 to 1400?
I also need a better light for my sump so I can actually grow something in there except the little shrimp that seem to love it.

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