Is This A Magnesium Deficiency?

Gowing indoors. Just started 3rd week of veg. They came from clones. They get top fed once a day for 5 mins by a drip emitter. Roots hang in a nutrient reservoir.

They are rooted in the smallest rock wool cube and then placed in a basket of hydroton.

Using RO water and was told that a calcium or magnesium deficiency was possible.

[video=youtube;BOwpB3J8lis]http://www.youtube.com/watch?v=BOwpB3J8lis[/video]

yea that looks like mag def.

A new res full of Calmag really had an immediate impact. Thanks everybody for the quick ID on my problem.

Probably and N def because your nutes ph is out, make it 5.8 asap.