Purplematic & White Widow

I considered it the day that the first 'true' leaves started developing. For me that was: Germination "week": 3 days...Week 1 starting on day 4 after putting seeds in moist soil.

I would think best way to figure out would be the following: Check your volume, ppm and pH measure every 24 hours. You will see how much ppm & water the plants are going through every day and what the related pH change is. If you have a very high base pH of your water supply and have to add lots of pH- to get to where you need to be after adding nutes, once the ppm has depleted you may experience a yoyo effect. Along that line (from the other side) that if you fill up a 5L res to say 500ppm (as an example) and overnight your res loses 1L but the ppm is now 750ppm you need to dilute to bring it back as your nutes are effectively more concentrated due to the drop in your res and it is almost certain this would cause a pH swing too. I would suggest diluting first to fill the res and then ppming to where you need to be, wait 5-10 mins to let it circulate and then pH it - you may find that you can plot a bit of a course over a week, figure out roughly how much water and how much ppm is used per day and make micro adjustments every so often for topping up res and adding nutes and pH - rather than trying to hold out for a week at a time. Like rasta said below - air quality on your bubblers can effect pH too.

You could build a drying box out of cardboard to dry inside tent and keep it dark. If they both share the same resovor, you will be flushing both. No the fresh water won't hurt but you won't be feeding nutrients either.

For the highest possible THC concentration( milky trics ) It looks like its 1-2 days(mostly milky with a few clear and a few amber). For a good balance of Head high and Relaxing high I would say you have 3-4 days(mostly milky with no clear and several amber). and for a couch lock mellow high you have 4-6 days( Alot of milkey with 10% amber). Its best to harvest right before lights on. If you cant do it right before your lights on time then extend the dark period up to a max of 24h. Happy Growing