Lower leaves turning brown, crispy starting from tips

[dreamtide]

So i've noticed that the lower, older leaves are dying and turning crispy and brown. It starts from the tips and spreads until most of the leaf is dead. i know its a travesty, but I don't have a pH meter yet. new growth looks mostly healthy, except the very tips are a bright yellow color on some of the plants (not sure if thats related). does anybody have a clue what this is?





info
first time grower

400w HPS
14 inches from top with batwing reflector
there is a fresh air supply
running on 24/0

medium: OF in 5 gal containers

water with filtered water
I fed once about a week ago with 1/4 strength nutes veg nutes from
I have no pH meter yet.

indoor grow room
2.5x10 closet
temperatures about 78-85 with lights on

growing white widow cheese auto
plant is almost 4 weeks old grown from seed

 

[namvet25]

http://www.growweedeasy.com/marijuana-symptoms-pictures Looks like cal-mag def, and possibly phos def also.You should have a PH meter to see where your at.Remove all those bad leaves and give them some cal-mag,along with some phos and potassium.You should also flush them well than add the camag and nutes.A ph meter is very important ,so try and get one and check your PH.

 

[dreamtide]

Thank you for your input!

I just ordered some Cal/Mag, but it won't be here til mid next week. I think the cal-mag deficiency was caused by me using filtered water.

I just set out some tap water to evaporate and will feed tomorrow when the water is ready. Hopefully it'll help out a bit.

 

[namvet25]

While your waiting for your cal-mag you can use reg unsulfured molassis at one tbl per gallon.It contains calcium and magneisium.