my eth is not stable

[callramy]

hello

kindly i want to know what is wrong of my rig the graph pf nanopool is not stable my hash rate is up and down as shown
http://imgur.com/XL2G3Gl

[mining1]

Don't know about their graph, but all you care about is getting as reward an amount as close as possible to what calculators say. Difficulty is constantly increasing so you'll usually get less than what calculators say, based on how much it increases.