Growing Cali Kush

so i have been growing cali kush and i will post some pics once it gets further into the grow but its been 3 weeks and it seems like its growing slow but its looking healthy is there a reason for the slow growing? does kush grow slower than others

make sure your temps (room temp, water temp etc ) are not too high....or too cold...either way will stunt and or kill them,,, and its a good idea to check the temp of your tallest buds ( canopy temp ) just to make sure your not gonna burn em if you are like me and bring the light down as far as they can take it