1st time grower!!!

How big should my seedlings be at one week??? I have two different strains and the one is noticeably smaller and seems like it is not growing!!! However it is green and straight up and down. It is white rhino and I know they are smaller plants but should it only be an inch tall??? Also should have my lights on for 24 hrs a day??? I have them on now for 18 hrs and off for 6!!! Can anyone please help if pics are needed I can post!!!

Keep the light on them 24 hours. Don't flood them every day. Plants are all different. Some may take a while some may not. It's all genetics.

u should go 20/4 or 18/6 plants need a moment of darkness to help with photosynthesis

dilly said it best bro.....slow down on flooding check your ph keep it between 5.5 and 6.0 and give it time

I have them in an aeroponic system that is on 24 hrs a day misting the rock wool for now until the roots are out of the block!!! So 24hrs or 18/6 is the question with the lights??? Anyone ever grow white rhino small plant???