What deficiency am I dealing with?

@moafya I'm already at that point. I use GH flora tripart nutrients. I had N tox from beginning and a little bit of burned tips. I stopped giving the recommended dose of the bottle and started giving 1:1:1 (grow:micro:bloom), but laid a little low on the grow, but not much. The burning got worse and darkening of the leafs didn't improve. I still went for 1:1:1 but also gave calmag (for rust colored spots). And layed down on the grow part more and more with every waterchange. Darkening didn't improve burned edges spread more but staid on bottem leafs. The water that was in it before the current had 1:2:3 and no calmag for the first time since pretty much the beginning. Now the burned tips and edges has pretty much spread all over the plant. I gave new water Saturday. It had 0:1:3 and 1 part calmag again. I made a new batch that's feeding my RDWC now that has 1:1:3 and again 1 part calmag. Burned edges are still getting worse and moving up the plant. Faster then ever. I just calibrated my ph/EC pen and it was of a little. so water was at 5 8-6.0 the last couple of days

Hi! As the time goes on with N toxicity it will show burned edges and burned and rust colored spots. From the pics I could not see any other relevant symptom other than those related to N toxicity. Keep doing the thing with less N and you will be safe. if your plant shows new burned edges as time passes by then you should investigate further.

@moafya I had N tox since week 2. I laid down on it and gave less and less. My new water contains 0.3:0.3:3 (grow:micro:bloom) of the GH flora tripart. It also has 0.3 calmag. So 750ml of each and 230ml of bloom rougly. N tox finally seem to improve. It gets brighter green near the bud region now. But I was talking more about the burned edges and those burned and rust colored spots

it seems you are facing N toxicity. slow it down a bit.

Those are caused by pH fluctuations. Can be quite common in DWC as the plant is stressed slightly with res changes and so forth. Other than that your plant is looking great...Keep up the green work