Vallisneria Spiralis Wanted

[1uke]

Hi, My sons newly setup Musk turtle tank needs some more plants but funds arn't great as just brought all the turtle gear etc.
 
I'm after some Vallisneria Spiralis around 20 I guess to try hide the filter and heater area.
 
Also if anyone has any other cuttings or plants there swapping out which would grow well in lowish tech?
 
Thanks.