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Sick plants, dunno whats wrong


New Member
Hi my plants are sick and i dont know why. i believe it is nutrient burn, but it was a week ago i started flushing them and they started to show improvement, and then back to "normal" for me which is burned leaves and almost no growth.

Plants are from bagseeds around 6-7 weeks old

running a drip system with rockwool
water 1-2 times per day depends on water left in cubes

PH always 5.7 when watering

water 19-21*C
Air 26-28*C

Humidity : 30-35%

250W MH 10-15cm from plants

Canna Aqua A+B, rhizotonic + cannazym

Any help would be greatly appreciated by me and my green buddies ;)


New Member
Re: sick plants, dunno whats wrong.

IMO,,,, it might be to much water.... rockwool holds water really well...


New Member
Re: sick plants, dunno whats wrong.

ok, but if i wait longer before waterings the roots get brown and die under the rockwool :(, is that normal?

its my first hydro grow, and everything seems to go wrong


New Member
Re: sick plants, dunno whats wrong.

i use rockwool for clones only,,,, the roots are in a DWC... my rockwool gets dried and NEVER wet again,,,


New Member
Re: sick plants, dunno whats wrong.

ok, I am going to use ebb n flow for flower but they still need to survive until then, and hopefully look a little better

thnx for your reply, odd as its was though ;)


New Member
how big of cubes are you using?....


New Member
I'm really not a hydro guy, but here are a few thoughts.

The muliple symptoms look like maybe pH lockout.
5.7 seems low, the stuff I read shows 5.8-6.8 for hydro. I target 6.7 for my soil.
Are you testing your solution after all nutes added, or just the water?

Your lights are only about 4-6 inches from the plant? (10-15cm)
I would make that 2 or 3 times higher for a while.
Especially since you have the reflective covers under them.... they may be getting cooked.

Also your temperatures of 82f (26-28C) are pretty warm. Some plants like it lower, maybe 75f.

Are you running 24hrs light? You might try 18/6, after the first few weeks I like to reduce to 18/6 and the plants seem to like it also.

Like I said, I'm not a hydro guy and even less a fan of rockwool.
Those cubes don't look very big, I expect the roots are air pruning themselves.
Like medme said, rockwool holds water very well. The first time I used dispensery clones (in rockwool) I darn near drowned them.......it also crushes easily and you lose the air pockets. Same result.


New Member

Ok, that sounds really high for hydro, 5.2-6.2 is the range i always stumble across :/
I dont use nutes yet, tried it a week ago at 1/2 (600ppm total) of the strength and in 24 hours they lost a couple of fan leaves each and 2 plants died, so i went back to water and 1 ml rhizotonic/L (200ppm total) for a week now and they still keep drying from the tops inwards on older leaves. (same symptoms but slower) thats why i thought nutrient burn

ok that is easy to fix, i do have a cooltube so the temp is same from 20" as it is from 5" thats why i put it there.

yes that is something im working on :p

no, i have 18/6, they do seem to grow more during night than day though :/

haha, if i could remove the rockwool i would, worst shit in the world.
but im almost 100% its not over watered, lost 1 plant duing the night because of drought, i lift them up and if they weigh almost nothing i turn on the drippers

Things to point out though, i did NOT wet the small rockwool cubes and not enough with the 3" i believe, but those PH problems i had because of that 4-5 weeks ago is gone, but inside the RW i dont know :/
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