Plants drooping suddenly

[happygoluckygeek]

Currently at week 3 of veg, plants looked really happy until watering 2 days ago. I noticed 2 of them starting to droop yesterday, now all 9 are drooping. Also starting to noticed some yellowing of the leaves. I'm trying to find out if its a lighting problem, fan problem or nutrient issue.
I have been following the coco feeding chart, so I did not change the amount of what I watered them before.
I have 9 THC Bomb clones in 4x4 tent
Canna coco
600 watt light 27" from top of plants
75-82 temperature top of canopy
watered with RO water, PH between 5.7-6.4
3 liters of water prepared with:
6.5 A B
6 rhizo
7.5 cannazym
2 ml calmag

each plant watered until about 20% run off
thinking the fan may be too strong even though it's on the lowest setting.

 

[Flockshot]

My first guess (and it is only a guess) is that they are root bound in those little cups.

 

[happygoluckygeek]

No Title

In previous grows we had issues where the plants were growing too stemmy and not bushy enough, and also growth was taking too long during veg. We asked for advice at our hydro shop and were told its good to leave them in the solo cups until they reach 12" tall. Just checked and they are average 11" now so I will transplant to 3 gallon pots tomorrow.
Also i forgot to mention that the watering before they were flushed. We were also told its good to do weekly flushings which we hadn't done in previous grows. Noticed tips were starting to turn brown and when I looked it up online i read it could be over fertilization and would be good time to flush so decided to follow to advice we were give. I took a picture of the roots, let me know what you think.

 

[alltatup]

Welcome to the forum, geek!!!
Definitely root bound! I am a DWC grower myself, but I'm surprised they told you to keep them in little plastic cups until they were 12" tall. That seems way too long of a time.

 

[Flockshot]

Just out of curiosity, the next time you go to that grow shop take these pictures and ask them what they think is wrong.

 

[Jibblerjoe]

Any time they go happy to droopy . If you plant pots are plastic, or in soil plants don't do well when roots run out of space. If roots are really rootbound, they will still have a hard time after transplant.

 

[Jibblerjoe]

Leaves will tend to yellow on lower part of plant.