Week 5 of flowering, serious ph problem. First time grower.

[DutchTreatMaster]

I noticed one of my plants(Blueberry Cheesecake) was getting yellow leaves at an alarming rate about a week ago(week 4 of 12/12), so I ordered a ph meter. The other plant, Dutch Treat, seems to be in much better shape with only a few yellow leaves and some purple in the top leaves.
It turns out the run off is 4.5ph. What should I do?
The Dutch treat should be ready to harvest in about 3 weeks and the BBC in about 5 weeks. Should I flush the BBC given it has a lot of time left, and simply try to correct the ph of the DT given it only has a few weeks left and looks pretty good?
Any hints on how to flush the 5 gallon pots? I read flushing with 3X the pot size would be needed, but do I really use 15 gallons of water to flush the plants?

Thank you!

[Gingerbeard]

You're cool.

https://www.growweedeasy.com/cannabis-flowering-stage

[DutchTreatMaster]

I have read the linked materials several times and again after your comment, but sadly I am still unsure on what to do and probably need some reinforcement as a rookie. What do you mean, I'm good?

[Gingerbeard]

The leaf discoloration is normal in flowering. Even mid cycle. Some plants don't lose a leaf while others lose every major fan. Purples are also common. Strain and lower temperatures at night can bring them on. The first time I got purps I was over the moon. I still get a little tickled when I think about it. Might have to drop a picture.
What sort of seeds are you using: regular, feminized, or autofem? How old were they when you switched to 12/12? When you switched to 12/12, did you change to flowering nutes?
Flushing is nothing more than a real good watering and it is never a bad thing unless the soil stays wet.

[DutchTreatMaster]

Feminized. Been following the fox farms nutrient trio schedule at half strength since week 4 of veg, but haven't been flushing as listed on the chart. So yes nutrient mix changed leading up to and when flowering phase started. Switched to 12/12 at day 60 of veg.
I probably will just flush the plants when the dutch treat is two weeks from harvest(a week from now) to avoid any chemical taste and with the goal of also getting the BBC plant into the 6-7 ph range for its last 5 weeks of flowering. Docs on the seeds suggest DT will only need 8 weeks of flowering and BBC will need 11 weeks.
Note to self to not grow tall and short plants at the same time that have different timelines for flowering.

I appreciate the help. Makes me feel much better!

[Gingerbeard]

Glad to help.

Switching to flowering nutes means you dropped your nitrogen. That's part of your yellowing. Since you're changing the nutes at the same time, they will show the same signs at the same times.

Everything your breeder tells you about their products are best case scenario and averages. Base your harvest time on trichomes, not recommended flowering time. You might decide to flower for more or less time based on what you want out of the plant. Check out this link. Another invaluable tool.

Give us some up-close bud porn. Best you can. We love the bud porn.

[DutchTreatMaster]

Ask and receive - comment with photos posted

[DutchTreatMaster]

Here they are. Need to work on the lighting, but the buds do look pretty good even with the fan leaf trouble...

[Gingerbeard]

Real fine plants DutchTreatMaster . I'd be proud to call them mine.