Dutch Passion Auto Ultimate Yellowing

[Zootown68]

-Problem: Lots of lower leaves yellowing, couple of upper leaves half and half
-Medium/grow method: Soil - Fox Farms Ocean Forest
-Feed and supplements used: Water only till a week ago, now Fox Farms trio at half strength every other watering at +/- 600ppm at 6.5ph. Alternating water and water and nutes every 4 days.
-Water source: RO ph at 6.5
-Strain and age - DP Auto Ultimate at 39 days
-Climate: Temps are 78 day 72 night and RH is at 50%. Carbon filter running on AC infinity fan. Wind tunnel-like conditions
- Light used: 18/6 Light cycle with lights off during hotest part of the day. 2x viparspectra xs-1500 LEDs
-Additional info: It's looked yellowish for about a week.

Have not been watering to runoff. Scared of overwatering. Any help would be greatly appreciated! Thank you all!

 

[RustyStarbuck72]

-Problem: Lots of lower leaves yellowing, couple of upper leaves half and half
-Medium/grow method: Soil - Fox Farms Ocean Forest
-Feed and supplements used: Water only till a week ago, now Fox Farms trio at half strength every other watering at +/- 600ppm at 6.5ph. Alternating water and water and nutes every 4 days.
-Water source: RO ph at 6.5
-Strain and age - DP Auto Ultimate at 39 days
-Climate: Temps are 78 day 72 night and RH is at 50%. Carbon filter running on AC infinity fan. Wind tunnel-like conditions
- Light used: 18/6 Light cycle with lights off during hotest part of the day. 2x viparspectra xs-1500 LEDs
-Additional info: It's looked yellowish for about a week.

Have not been watering to runoff. Scared of overwatering. Any help would be greatly appreciated! Thank you all!

View attachment 1343295View attachment 1343296

Hello mate, just noticed no one had replied yet bud... Looking at the new tips and the fact that it's yellowing from the bottom up now... Plus the the fact that you started feed a week ago and the yellow started then?
Its possible that the feed is too strong too quick.... They often make the feed charts for photoperiod strains and Autoflowers often need a bit less than the feed chart.
I would Lose the nutes for a few days and water with pH water until the new leaves come out greener without burnt tips and then re introduce the feed to a quarter of what it says per litre and watch her for re occurring tip burn.. Raise the feed slowly...hopefully this will spark a few more views and get some other advice good luck. Bro, tag me in if ya like and I'll help if i can.. I've not used fox farms, but I'll ask about mate

 

[Zootown68]

Thanks, @RustyStarbuck72! Seems a good plan to take it a bit slower on the nutes. One can always add more, but adding too much could spell disaster. I'll do some more research on the Auto Ultimate's typical feeding preferences as well.

 

[Zootown68]

I ended up putting five gallons of pH'd RO water through the plant and runoff is still at 600 ppm. Should I keep going till I get closer to zero Ppm? Been a couple of days and still looking yellow compared to my other two plants.