Over fert?

Hello, im a first time indoor grower. These are clones about 1 month old in veg.I changed the nutes and the newer leaves have started to curl upwards.There is no yellowing or any other symptom other than the very tips of some of the leaves have browned up but just 1/8 inch other than that they look pretty healthy.I am using Flora nova grow at 600 ppm I have cut it back to 300 ppm after a good flush.My babies are growing in coco choir and pea grave(ebb and flow)
Its not heat stress.The lights are two 2' floros with 600 lumen grow lights from home depot they dont get very hot at all.The strain is a sativa indica cross called great purple.Ive looked through other forums and i think its over fert but im not sure.Ive also read that it could be salt buildup. If any body knows anything that would help please help a brother out.Here are some pics sorry for the quality

did i put this in the wrong forum?

No your in the right one. That plant looks healthy to me. If your tips are just a bit burnt its ok, just dont push the nutrient levels any more. I do things really gradual in efforts not to shock the plants. So when stepping up or down on the nutrient mixture I do it gradual. It takes several days for signs to show up some times, so going about it slow gives me time to react to problems. I hope this helps LOL, at least its a response

They look healthy to me too. A PPM of 600 isn't too strong in my estimation.

Vi

I myself am not an expert but makin a few mistakes in the past allows me to say in my opinion, I dont c en sighns of nute burn or lock out.
how often does ur table flood? They seem 2 b ok but ull want 2 dial ur system in a bit ... Keep it up ull get it with time.
Happy Growin......