PPP firstly is a beautiful high yeild plant i love it and when it finishes looks great with it's reddish colour. Now growing it myself again and will keep it by making clones from it a great plant.
OK smell, smell needs to escape if you have only a couple of plants and no ventilation it will will slowly but surely start to build up.
A build up slow smell of cannabis is a dead cert for a grow. Just be careful try to vent out of the place completely if you can so there's no chance or the smell being struck in the room a carbon filter i think is always best imo.