New Grower Little help please

[Greengrower]

Hi guys!
My plants are yellowing a little at tips of new growth (pic 3) and one is also showing some purple/red?(pic 2)
Also why does new growth look so week and curly? (Pic 1)
What could be causing this please?
I'm in soil (biobizz light mix with some additional perlite)
Temp ranges between 18c and 27c
Currently 21 days old
Autoflowers
Watering once every 36hours roughly 500ml
No nutes or anything yet.
Rh is around 45-50% mostly but can drop lower occasionally.
Thanks!

 

[Fitzy]

So to me I think it's a micro nutrient on the first the others are hard to tell for me but they also seem to be curling at the tip( clawing) which is from too much nitrogen I know u said u didn't add any way strains are they? are they mephisto?

 

[Greengrower]

So to me I think it's a micro nutrient on the first the others are hard to tell for me but they also seem to be curling at the tip( clawing) which is from too much nitrogen I know u said u didn't add any way strains are they? are they mephisto?

One is sweet seeds dark devil auto, that's showing signs of clawing and tips yellowing. All the rest are Dinafem Critical+ 2.0 auto

 

[Fitzy]

One is sweet seeds dark devil auto, that's showing signs of clawing and tips yellowing. All the rest are Dinafem Critical+ 2.0 auto

Sweet seeds I've seen odd growth I hope she snaps out of it the Dina girls seem ok they will grow out of it in less than 10days that's my gess

 

[Waira]

Start feeding mate!... Yellow tips are pretty generic symptom, not always burn/toxicity signs,... given your low feeds, this is an early defc. starting can't say what yet but no matter, solution is the same-- feed!

 

[Greengrower]

Start feeding mate!... Yellow tips are pretty generic symptom, not always burn/toxicity signs,... given your low feeds, this is an early defc. starting can't say what yet but no matter, solution is the same-- feed!

Thank you Waira!

I last water they had I have them 0.25ml of feed per 500ml. Think this is too low? I'm due to feed again in the next 12-16hours and I'm wondering if I should feed again or if I should go with plain water?
I'm in biobizz light mix and I'm only feeding biobizz grow right now. Also I feel my ph is probably a bit high (around 7.5) would bottled lemon juice (that's from concentrate) do a good job as an organic solution? I do have regular pH down but I've heard that adding that in to an organic set up can be bad?
Thanks!

 

[Waira]

ease it up more, that very light and BB nutes are on the mild side....
What's your water source, ppm's? 7.5 pH hints at significant hardness... adjusting with citric acid/lemon juice is OK...

 

[Greengrower]

ease it up more, that very light and BB nutes are on the mild side....
What's your water source, ppm's? 7.5 pH hints at significant hardness... adjusting with citric acid/lemon juice is OK...

Thanks again Waira!
I ended up feeding the same as the first time, should I up it for the next feed? One of my girls is going into her pre flower stretch so going to get some bloom nutes in her feed. I can check the ppm later. Also the leaf tips are looking worse now? What would you recommend?
Thanks again!

 

[Waira]

It takes some time for the nutes to get in there and symptoms to halt,... I recommended feeding more, at least half strength, 75% of whatever the recommended dose is on their feed chart... Meantime, you may see some progression of symptoms..
Another thing you should pick up is an in-pot pH soil probe to test what's up in their... The Accurate 8 (Control Wizard products) is a good unit, you may find it under a different brand name in EU (Amazon), but it all comes from the same Chinese factory! Look it up online and you'll see...
Organic or not, pH can and does drift out of range sometimes in-pot, and run-off is crap for accuracy of pH....

 

[Greengrower]

It takes some time for the nutes to get in there and symptoms to halt,... I recommended feeding more, at least half strength, 75% of whatever the recommended dose is on their feed chart... Meantime, you may see some progression of symptoms..
Another thing you should pick up is an in-pot pH soil probe to test what's up in their... The Accurate 8 (Control Wizard products) is a good unit, you may find it under a different brand name in EU (Amazon), but it all comes from the same Chinese factory! Look it up online and you'll see...
Organic or not, pH can and does drift out of range sometimes in-pot, and run-off is crap for accuracy of pH....

Thanks again for the reply Waira! I really appreciate the help!
Last watering I did included 1ml per liter of biobizz bloom. I'm not really following a feeding chart though lol, I'm just going slow and steady. I've seen the feed chart I should be using so I'll re-find it and go from there!