Do they have foxtailing by any chance?Interesting I have noticed that I do not get nutrient burn even on the tips and I let the plug get up to 2800ppm! which is like 5.6EC! I have a UV light on but tbh, I don't think it does anything. The only red are a few diodes in the xs1500pro and the whites are 6500K and 4000K so that shouldn't be a problem I would think.
