Grow Mediums HELP NEEDED PLEASE!!

[Joeypuskin]

I'm starting to get lime green leaves that curl under? And it's only on half of my plants?

I'm on day 8 and I've fed them 1/4 strength nutes.

I'm growing in rockwool and eventually will have them on my nft tray with a 100 liter res when roots are showing

Got them under a 600w hps
Temps are constant at 26 Celcius
And humidity at 40 % I do plan on getting a humidifier tommorow
Have I over fed them? And should I flush?

And help would be massively appreciated

 

[wynnyin]

Can you take a photo without the hps?

 

[Joeypuskin]

This is the seedling that's the worst....

I have tested ph and the run off was 7.00

I double soaked my cubes in 5.6 for 1 day each

 

[Joeypuskin]

@wynnyin

 

[Joeypuskin]

I know the 7.00 ph is high and should be in 5.2 to 6.2 range

 

[wynnyin]

Im new to hydro mate but on first look I thought they were overwatered. Can you pick them up and feel the weight of the cube and compare it with a plant that is looking healthy. If its noticibly heavier then dont water for a couple of days and then only water from the outside.
I try to keep my ph as close to 5.8 as possible as I messed up by not checking the calibration of my ph pen luckily hydro recovers fast but getting ph correct is essential. Also I have read rockwool can mess with ph so better to get ph right.
I would post in the infirmary and see what more experienced hydro growers say.

 

[derek420colorado]

Overwatered as stated above, when using rockwool at first you soak in ph adjusted water then once you have soaked in ph adjusted water and let it DRY all the way out. Then you want to drop the bottom half of the cube in water for just a second or two so that the bottom half is DAMP not dripping wet and the top half is dry. What this does is promote the root growth in the right direction and it prevents the curling leaves and overwatering. Here is a link to my last DWC AutoXtreme grow and I did a pretty thorough job of explaining things(or at least I thought I did lol) so you might pick up some tips. Hope this helped and Happy Growing!

 

[Joeypuskin]

Thanks guys letting them dry out, have taproots poking out of a few of the cubes, will fill the res and get the nft table flowing which will control ph abit better because of the size of the res and set these baby's away big time

I did soak the cubes twice in ph'd water to 5.6 @derek420colorado and thanks @wynnyin for the advice

 

[Joeypuskin]

Thanks for help guys, ran ph'd water in the res on a slow flow for 2 days then added some
Nutes to the equation...roughly about 1/4 strength and raised the lights, they've responded quite well.
I havnt been up today but will be in abit to have a look at the res so will chuck some pics up to see where there at