Dense or sparse plants

[Kryten]

I have a newly cycled 19 UK gallon tank that currently houses 12 plants. The bottom of the tank is densely covered, but the plants that will fill the top half of the tank haven't yet grown very full

Is it best that I buy a couple more plants or should I just encourage growth of the existing plants

Any help would be much appreciated. One of my Platys is getting fin nipped by a broody zebra danio and I think it might be because there isnt enough foliage for the little fish to hide in

 

[StiX]

Do both! Get afew more plants and encourage them all to grow, the more plants the better IMO