first grow. what could be the problem

Well i started my first grow on the 7th Feb 2007 and so far so good i guess untill i noticed that my leaves were burnt to sh!t when i came home and saw that after i had changed the nutrients to full recomended power that morning. what do you think could have caused the brown crisp leaves. now i dont have a pH tester or the up or down solutions which i wont have till monday. mysetup includes an 4w x 8d x 7h with a blower fan and a 400w HPS bulb and ballast

It may be one of two things. HPS bulbs get very hot as opposed to fluorescent or other kinds so they should be kept quite far from the tops of the plant, especially when young. My other piece of advice would be that it may not be ironic that the first day you switched to full strength fertilizer this happens. Maybe check the light distance (I'm not sure off hand what it should be) and try laying off the fert for a while. Those guys are still little.

Hi, Tokinj ...

Those are just babies. There is no way they should have been given full strength nutes.

Vi

^^^^^^ Ditto

are nutrient percentages of 30-15-15 and 15-30-15 too strong?

Tokinj ...

It's not the chemical make up of the nutes that got you in trouble ... its the fact that you gave them any nutes at all. I grow my seedlings and clones in a bubbler using 2" net pots and 1" Rock Wool cubes. I've gone over 60 days without giving them any nutes at all ... only Reverse Osmosis water. Of course, I really wasn't trying to get them to grow big ... I was just waiting until there was room in the larger vegging cabinet for them.

You have your babies in Rock Wool cubes. Are you planing to grow them out in a hydro setup?

Vi

it think i am giving them to much nutrients too...... i 'm diluting the half strength mix down so its equivalent to 1/64th strength and moved my 400w HPS up to 18"inches within tops of plants i also added a humidifyer to the room as well and put aluminum foil on the walls till i get mylar.

oh and yes o do intend to grow in rock wool till flowering i was also considering to move one or two out side during the spring/summer but i face the west so i may only get 5 or 6 houurs of direct sunlight at the most
in the after noon till sunset and thats only after daylight savings hours in march.

MY SETTINGS:

yep you gave it too much nutes too soon, but it looks like Ur off to a decent start...U should start a Grow Journal