Hi I’m new on here and forums in general (hope I posted this in the write place) also my first DWC and I’m having a problem slight yellow on my leaves and browning on the ends think it might be nute burn but I’m not sure. My temps are 21c humidity is 45% water temps 18c I have kept it at 5.8 checking a couple of times a day. Now my water is hard at about 250ppm and I fed the plant at less than a quarter strength and my ppm went up to 400 I thought it would be fine but then I started to have these problems so I switched back to tap water. My RO system just came in so I will be switching to that as soon as I get it all setup. So I’m just wondering is this nute burn? Any help would be appreciated.