flowering (is there a problem)

my plants are 14 days into flowering and only have like 2/4 white hairs i have seem ppl wi small buds at this time is there any reason why its going so slow im in hydro bubble poni setup using water ph5.7 and adding rapid bloom part a and b every other day under a 600 w hps and i have 3 plants on the 12/12 cycle any help

the plants habve more than dubbled almost trippled in size aswell

cheers

As well as all the environmental variables having an effect, different strains take more or less time to switch over to flowering.

cheers just unusual changer water in res today to try that