Yellowing new growth.Not enough nitrogen? To much nitrogen? Ph fluctuations?

[Bitzer malone]

Hi friends.
hoping someone could help me out. Here’s my situation.
Dwc photo period. Using quarter strength canna aqua nutes. Did a res change about a week ago and my ph was a little crazy. Kept climbing from 5.5 to high 6’s or even 7 over night for a couple of days. Now the ph is more stable and is dropping slightly each day. I don’t have a ppm meter at the moment ( waiting on it arrival via mail) so don’t know what ppm levels are. Just using ph’ d tap water. New growth is looking yellow beginning from base of leaf. Bottom leaves are nice and green. Just new growth affected.

 

[NuttyProfessor]

looks like iron locked out with high ph , ( i think ) maybe needs half strength nutes now, and sometimes leaving the nutrient mix for 10/15 mins then ph it helps to get it more stable after a good stir , iron goes for new growth so this is what i am thinking , im sure the pros will help you out i do not do water grows any more , to much hassle for me lol