First let’s clarify: 1.6 EC would be around 800 ppm on the NACL (500) scale. I would verify your ppm as reading ‘500’ and not ‘700’ to avoid confusion. Or just use EC.
800 ppm isn’t bad with GH but could bring it up to 900/1,000 ppm (1.8 to 1.9 EC) for the rest of veg. Do a drain and flush at transition (different schedule) and again once in flower. This is not hard and fast but your setup may allow more or less leeway. Some growers change rez once in a grow.
How about some more detail along with a picture in white light?