Need some help please. My setup:
50/50 mix FFOF/FFHF mixed 15-20% perlite. 2 Mars TSW2000 at 85% approximately 32” above plants. 2 Bruce Banner 1 Pink Runtz 1 Cheesecake Gelato. All autos. Day 21. No nutes. Organic will top dress day 28(next wk). I didn’t water (only misted the top) till day 10 then watered every other day about .25L per plant. Last 3 days watered same amount each day. The two larger plants gave .5L
2 plants are fine 2 have this yellowing
Just starting to see some white hairs shooting so I know they are entering preflower.
Is this a cal mag issue? I know everyone is always quick to say that but this looks like it might be?? Just don’t need any issues and want healthy plants.
Yes, I keep my pH range when watering to 6.5-6.8 range. Just calibrated my pen so don’t think it’s that. My avg high low temps. 65/80. RH 45-50%
Howdy
What size pots 
I have no experience with FFOF, not available where I am.
I reckon they need more water than that .{500ml}
Need to water till get some run off.
Need to have wet and dry cycle.
@ChittyChittyBangin
What do you think Chitty?
If youre using FF i would do a slurry test to confirm your ph. Alot of folks were getting FF that had a tanked ph outta the bag. Look up soil slurry test on youtube.
Looking good Growmie, it’s time to increase the amount of watering. Overwatering is due to frequency and not the amount given at one time. I would suggest a drench to drought routine moving forward as in water to run off and let the medium dry before watering again. Catch a sample of the run off and test the PH and PPMS, the mix of medium you’re using should feed these plants for approximately 4-6 weeks 
Which ones are suffering the two with .25l water or the two with .5l water.
Kinda looks like nitrogen burn combined with no water to the roots. .25l to .5l water does not seem like enough to soak down to the root.
I would suggest watering with 1 full quart of water mixed with calmag ph’d between 6.5 and 6.8 at this point. [1 teaspoon calmag to a gallon divede by 4 = quart]
I would not water till run off those little guys would take a week or two till they went dry [lite pots] and I feel that is to much water.
After watering wait till pots are lite pick up pots before and after watering to know wieght of pot.
I also would not top dress with anything. Fox farm soil has all the nutrients needed for at least 4 weeks.
That being said they look to be getting to much nitrogen dark green leaves with crispy edges.
Again which 2 by amount of water are having troubles.
Forgot to mention I raise photoperiods butt babies are babies.
Also what size pot 3 gallon if so watering till run off will keep those babies with wet feet for a week or more.
Imo watering to run off in fox farm hf or of is not really necessary. It just washes out the nutrients they put in there for the plant to use for 4 weeks. When you start feeding nutrients it is necessary to wash out the old and bring in the new. Do make sure every watering is ph’d though.
Again I grow photoperiod not autoflower. So you could say I know nothing about autos or their care.
Thank you all. I did water more until I got a slight runoff last night and today the soil was still moist so holding water for today. Also added just a bit of calmag about 3ml per gallon. Good news there and they seem to be bouncing back.
@Chinzilla420
Howdy
That is great news 
