Advice needed please possibly plant problem.

I used to grow last year and i used rockwool and had no problems for a few grows.
I've just started a grow and i thought i'd give cocoponics a go..I just noticed one of my plants
has a lightening green band on one of the lower leaves and the bottom set of leaves on most of
the plants have twisted quite bad!!!
I think i've overferted them as i've been given them weal nutes every feed once a day. i would like
your opinion please so i can nip this problem in the bud..otherwise these plants look very healthy.
Plants are 3 weeks old from germination under 400w hps which is about 1m above them.
they are in 6.5 litre pots and i'm using cana nutes given in a water with a ph 5.2-5.8.
The grow room is at between 74f lights on and 60f lights off with a humidity of around 50.
thanks for your time.
Any ideas please?
forgot to say strain is magic bud.

I can't comment on your problem, but as I also grow in coco and use canna nutes I have noticed a couple of things you need to be aware of.

The PH range for coco is 5.8 to 6.3 (I aim for 5.8/5.9). My local grow shop also recommends that if you are using hydro nutes in coco, feed at 3/4 strength (this has worked fine for me, if a shop tells me to use less of something that they are selling me I am inclined to believe them - they also have a great reputation for good advice).

:hippy:

So for coco instead of using the normal ph range for hydro 5.2 - 5.8
i should be using the 5.8 - 6.3 range? might give it a go as i've had a few problems :(

I have used this range for 4 grows and had no issues (Well I had one issue but it was because I didn't have a meter for 4 days and used tap water with a ph of 7, as soon as i went back to 5.8 the issue disappeared).

The watering frequency for coco depends on how big your pots are. I use really small pots and water everyday (not ideal but it works for me), with larger pots it is every 2 or 3 days.

I forgot to mention how much water I use...

I stat my cuttings/seeds off in rockwool. Once I transfer them to pots I use about 150 - 200ml per watering per plant. I stick with 150-200ml a watering until either of these things happen...

1, I see a root at the bottom of the pot
2, The coco starts to become dry (don't let coco dry to the point where it becomes light brown)

As soon as either of these things happen, I start increasing the amount of water I use by 50 or 100ml each watering, until I reach the point where I am watering until run off.

(You might have to tweak the amounts a bit for your setup).

Please bear in mind that I am not an expert and I am still learning, there might be a better way, I am just letting you know what works for me.

I would also suggest doing a grow log if you have a camera. That way other people can spot problems in your setup.

Well thanks for all the help heres a update..i flushed and they didn't look healthy at all for the next week and i thought i'd lost em :(
But i brought some calmag addictive becasue i thought it was mag deficiency and that seemed to help alot....here pic of my baby girls 2 weeks into flowering :)

Looking good. :thumbsup:

Are you still using that low PH range?

I'm using the 5.8 - 6.3 range you suggested. i normally stick to 5.9-6.0 seems to be working ok.
Thought i'd lost em at one point. tough little girls aren't they.
thanks for your input :)