New growth has a gold/yellow color

I have a question about new growth on my dwc plants.
There growing like crazy, however the new growth in the center is starting to get the gold color in the middle and slightly out from the center just a bit. What does that mean? time to change water? its getting time to add about a gallon of water to the resv. the plants were put in on the 8th of this month.

Sounds like it may be a sulfur deficiency if I read your description right. Check out this link:

https://www.rollitup.org/marijuana-plant-problems/216537-self-diagnose-your-plants.html

thanks dave... ill check it out now