Your plants look fine. No sign of tip burn, not dark green, just a nice healthy green color. Nothing wrong with them they look healthy. Leave them alone.
Too often people start checking runoff, panic when the numbers are not what they think they should be and start doing things even though their plants are healthy without any signs of issues. I've seen many good grows go downhill because of the grower trying to adjust runoff values because they think the ppm's or pH is off based on the runoff. Flushing tons of water through or dumping high or low pH solutions trying to get the runoff to where they want it usually end up doing more harm than good.
Your plants look good. Let them grow.