20/4 worked best 4 me too,shame about mephisto I found them to be one of the best.There shouldn't be much difference, however I would still aim for some dark hours so I'd say go with 20/4
Had 2 out of 4 mephisto seeds not pop. Dunno if they are old or incorrectly stored but I’ve not had 1 fastbud seed be a dudUpdate: 2 of the mephistos sprouted with just one not doing anything. The fast buds has really taken off but the other two are barely growing. One just broke dirt yesterday and is still just barely out of the dirt