Why are my leafs curling under?

[mrxthethcman]

Most of the big fanleafs on my plants,they are starting to curl under.My ph is between 5.8-6.2,and my nutrients are at a CF reading of 20.Im using a flood and drain hydroponic setup,and my plants are 5 weeks old.The thing i want to know is why are they starting to curl under?. :confused:

[mrxthethcman]

Anyone plz????

[kryptobs2000]

I think overfert might cause that. Are the tips turning yellow too?

[mrxthethcman]

no the tips are green.

[sc0usa]

im far from an expert but isnt 20 a bit high?

check this video out

http://www.1-hydroponics.co.uk/video/windows-media/systems-p1.htm

[mrxthethcman]

No, that chap is talking about TDS total disolved solids.Its different from CF.

[sc0usa]

i read in ppm so thats all i know,hope you find the answer,gl :)

[Proof]

if there drooping over which i imagin them to be doing, could be not enough potassium (K) or ur overwatering?

[dHazed]

how often do you flood each light cycle? what is the medium?