Been a while, need a little help.

It's been almost 4 years since I grew last. Not really sure why some of my seedlings are turning yellow.

2ft by 4ft T5 4 bulb floros. Plants 3-4 inches away from bulbs

Medium is 5 parts coco coir 3 parts perlite.

Watering with distilled water.

High of 82 low of 66. Humidity fluctuates between 50% and 75%

Good air flow.

Ph is 6.5 to 7

Wondering if they need to be fed slightly. All of the plants in the middle are purple kush feminized. The outside plants are all just bag seed I planted a few days prior to the purple kush. Seems kinda weird because I have been watering the bagseeds with tap water and they seem to be doing much better, also I put just a little bit of EWC in the medium of the bag seeds.

When I water next should I use some ph down, maybe fert slightly and see what happens? Anyone else have problems like this? Like I said, it's been a while since i've grown. Any help would be much appreciated, thanks.

It seems like your doing everything right. I wouldn't feed yet. I made that mistake on my last grow. I wonder if the t5 is to close. You might try lowering the PH a little. I'm no expert for sure, but I started with well water and got off to a slow start. My well water ph is 7. I switched to RO water, and things got a lot better. You might give that a try.

Swap the distilled water for
Ro water and get your ph lower to 5.8 or so. If no improvement after a week than feed slightly maybe 500 ppm and see what happens

5.8? That's what I keep my hydro at...unless coco coir is considered hydro, and it may be, then you're looking at a pH of 6-7. 6.5 Optimally (in my experience with homegrown, no certain strain..).

*EDIT* RO water isn't a lot different than distilled, distilled just won't hold your pH quite as steady and have a different pH than RO. I used distilled for a long time and it worked great, just required more pH adjustments.

Yes. Treat it like hydro and use ro water, distiiled isnt the best one to use.

RO helps hold a more steady ph is the only advantage it has, along with being less $. Distilled should still work well though...and oic, I didn't know if that was considered hydro, thanks for clearing that up Chernobe!

Technically its called the fertigation method. Many commercial nurseries use this method becuase of how easy and cost effective it is. The water is prepared as if it was going to be used in a hydroponic garden so all of the same rules apply. Pretty easy and fun gives much better yields but thats just an opinion

Ooh I see, well I've learnt something new today! Haha I need to learn all I can, with this being my first go at hydro (DWC).

Thanks guys. I checked out Amazon and some RO systems and none are under 100 dollars. Am I looking at spending that much? Or can I buy a big tote, fill it was my tap water, put some fish tank bubblers in it and let it set out for a few days. Does that even work? Would it be that bad if I just lower the PH of my distilled water? Thanks again guys.

Get a few 5 gal jugs and go to the water machine at the liquor store or wherever. Its gonna be the right stuff coming out of the machine usually 1.50 or so for 5 gals. I wouldnt even bother with letting tap water sit out. Assuming that your local water supplier isnt using chloramine which cannot evaporate you will still be left with flouride and whatever else has been added to the water. If you use bottled water on your garden be sure it contains no sodium it will say so on the label. You could ph the distilled water but it is not the right stuff to use. Just get the ro and be sure to add cal-mag to it.