Grow Mediums Nute burn/EC levels

[Gooba]

This is my first NFT auto grow & I made the mistake of raising the EC too high/too quickly.

I started on 1.2EC @ week 1. The next resevoir change (week 2) was @ 1.3EC & the last resevoir change I did was to 1.4 ec (week 3) where i am now.

It was after this last change that i started getting yellow tips, So i lowered back to 1.3EC. They're growing rapidly (up to 1.5 inches a day) so I don't think the damage is too bad but my question is:

On my next change shall i attempt to go back to 1.4EC or shall i stick with 1.3? Is it a case of the bigger they get the more food they need or are autos happy with low EC levels throughout?

Any help appreciated.

Cheers

 

[Muddy]

Generally speaking, autos only require about half the strength that photo sensitive plant can tolerate. I grow my autos in soil less media, which is very similar to hydro. I normally start at 1/8 strength, increase to 1/4 around week 3, then to 1/2 strength by week 4 or 5, depending on the plant/strain. Seldom do I ever get above about 1,100 ppm, or EC 2.2. Just watch your pH to know how your plants are tolerating the nutes. If your pH drops and your EC rises, your nutes are too strong. Conversely, if your pH rises and your EC drops, your nutes are too weak.

 

[Gooba]

Generally speaking, autos only require about half the strength that photo sensitive plant can tolerate. I grow my autos in soil less media, which is very similar to hydro. I normally start at 1/8 strength, increase to 1/4 around week 3, then to 1/2 strength by week 4 or 5, depending on the plant/strain. Seldom do I ever get above about 1,100 ppm, or EC 2.2. Just watch your pH to know how your plants are tolerating the nutes. If your pH drops and your EC rises, your nutes are too strong. Conversely, if your pH rises and your EC drops, your nutes are too weak.

Thanks for the reply dude. I'm NFT with 3" rockwool cubes.

The EC has always been been stable but the PH was dropping until I knocked it down to 1.3, so I guess that means they're happy now :gthumb:

Would it still mean not enough nutes if the PH rose & the EC stayed the same?