Yellowed, and now some spots.

Okay, first off, I'm back after almost 2 decades of not growing. Needless to say, things have changed. Namely, I decided to grow hydro this time. I have a problem after 2 weeks of bringing home my first GDP Baby. Pics posted below. I have noticed that I am getting some yellowing and this morning, I have found a few brown spots that look to me like (N) burning. But since I am used to soil, but wanted to try hydro, dunno if this is really the case. Your honest help would be appreciated. Thank you

Now the info:
Strain Grand Daddy Purple
pH Runoff 6.2
Nutes FloraNova 1.25ml/L
N-P-K 7-4-10
Delivery drip 3x/day 15min Ea (lights on only)
Medium GroDan Rockwool
Lights 18/6 T5 6500k

hydro requires a lower pH, 5.6-6.0, 5.8 best. what's your ppm?

Yep, you are on a bad road there brother
You need to talk to some rockwool guys about this! I do not like rockwool, very unforgiving if you do not get your watering intervals right. I suspect that you are overwatering them, causing some lock out. I'm sure rockwool guys will chime in
I for one start them in rapid rooter plugs and go from there directly into hydroton. Watering issues as well as salt build up issues are easily dealt with in hydroton, just food for thought!
Good luck!
Kind

unity said:

Yep, you are on a bad road there brother
You need to talk to some rockwool guys about this! I do not like rockwool, very unforgiving if you do not get your watering intervals right. I suspect that you are overwatering them, causing some lock out. I'm sure rockwool guys will chime in
I for one start them in rapid rooter plugs and go from there directly into hydroton. Watering issues as well as salt build up issues are easily dealt with in hydroton, just food for thought!
Good luck!
Kind

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3x/day for 15min drip? thinking maybe shorten the intervals to 10 min?​

why would that happen? just control it

asaph said:

why would that happen? just control it

Click to expand...

Actually, I just check it again, and it had crept up to 6.9. pH Adjusted down to 5.8, we'll see how it goes.

A Ph of 5.8 is the sweet spot for any hydro set up and 6.8 for soil grower trust what there saying i grow both right now and i just harvested my BlackRussian i did in a 6x6 gorden cub and had no probloms always 5.8 or a lil under 5.6