Is my tank cycled?

[Maisielily]

I’m new to getting tropical fish so have began with a 22l cube tank with filter, heater etc. I put this together one week ago, adding water conditioner etc. I had to add a small platy since had no where else to go, 24hr later I added a dose of tetra safestart which I have read good things about. On top of this I added the filter cloth from a filtered tank, and some of the substrate aswell. A week on I have just tested it and these are my readings:
-nitrite:0
-ammonia:0
-nitrate:20
-hardness:120( I know that is high it has to do with my location however I’m visiting a specialised store which sells the rocks that can help lower this)
I know its only been a week but with tetra safestart, my platy and the seeded media could it be cycled?

 

[Colin_T]

If the general hardness is 120ppm then it is soft water.

There are no rocks that lower the general hardness (GH), but limestone & sandstone rocks, and shells & coral will increase the hardness a bit. They will also increase the pH.
There are filters/ resins that lower the GH but you do not need to do this because your water is soft enough as it is.

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Depending on where the established filter cloth came from and how much filter material you added, will determine on the bacteria in your filter. But it's unlikely the filter will have cycled in a week. If you check your tap water for nitrates and it has 0 nitrates, then the filter might be cycled. However, if you have nitrates in the tap water, then the filter probably isn't cycled.