How hard is to hard?

[metalman]

How hard is to hard? here are my tanks specs,

160 litres

PH 7.4

nitrite 0

nitrate 10ppm

hardness 300ppm

My fish seem stressed, I have only had my discus for a week now, and I have lost a small one, and one of my large ones colour has dulled to a very dark colour. Could it be my hardness and PH?? I have 3 others and they seem happy enough. I got them all from the same place and they all come from the same water conditions.

[Merrilyn]

Did you test the water they came from, or did you ask ask the shop what their readings are.

It's not so much the parameters of your water that are a problem, it's the change from one level of pH or hardness to another. Most fish will cope if they are introduced to new conditions slowly, over a week or so, but a sudden change will send them into shock and can kill them.

[metalman]

they came from a ph of 8.0 thats about all I know.