hydroponic minimizing hydroponic plant shock

hello,
 
so i had some great 3 week old peppers plants that are (were) doing very well.
after the 3 weeks i decided to i flush the reservoir and increase nutrients from 250PPM to 350PPM since the plants are now bigger (i was giving them nutrients @ 1/4 strength), but this minor increase seems to have shocked the roots because they were nice and white, a day after the nute change the roots are slightly darker and plant growth halted.. it's been about a week and the roots are starting to show signs of recovery (root regrowth) but i'm wondering if there is anything i can do next time to stop this from happening?
 
here is what they look like:
http://i.imgur.com/FP3LWLL.jpg
 
excuse the green light. the leaves are nice and green and they already have little flower bud appearing, but it was just the roots that halted growth..

Don't change nutrients. As it gets lower next time, just add the stronger mix to the existing one. I've never had root shock from doing that, and this is with increases a heck of a lot greater than that, such as 50% strength to 150%.
 
 
Welcome to THP, also from CT.

thanks.
 
that's what i don't get.. some people who grow cannabis say they flush with plain water for a day or two before adding nutrients again. to me going from no nutes to nutes should create bigger chance of shock when increasing nutrients.
perhaps it could of been a different thing altogether because now that i think about it i didn't dechlorinate the water long enough. not sure if going from no chlorine to a bit of chlorine will shock the roots.
 
cheers