ice in DWC

There are several ways you can develop the anthocyanin in your grow - one is to reduce the nighttime temps during flower (into the 40s if possible) but it sounds like you're past this stage and it may not be economically feasible for a lot of growers. Another way to bring out the purple is to reduce your light cycle during the entire flower period down to 9hrs on, 15hrs off. A cold water flush with water temps of 40 or so will also help to bring out the purple and some growers will do that for an extended flush of 7 to 14 days but a normal flushing cycle will also work... Basically, in order to bring out the purple, you want to gently stress your plants and these methods will do that.... Good luck!