sick plants~~~~pics

[kctats13]

I read through the nutrient trouble shooter sticky and have been searching the forum and I think I might know the problem but im not positive so i wanted to get some feedback from my fellow growers.

OG kush clones
DWC (homemade 18 gal rubbermaid)
2- 12" air stones with a dual outlet pump
6 inch net pots with hydroton
Botanicare pure blend pro grow nutes 3-2-4
plants are 8 inches tall and 2 weeks old
600 watt hps hortilux
ph 5.8
temp 75 degrees and 45% humidity
60cfm fan for ventilation from outside
ppm??? not sure im waiting for my ppm meter from ebay

So the leaves just started curling up and the leaf tips and edges are brown. The roots just started growing into the water a day or 2 ago and now this is happening.
Right away i figured that my ppm's are probobly way off just because i have no way to check them but im not sure.
The plants seem to be growing good besides that.
Heres some pics
What do you guys think? Could it be my ppm's are off? Everything i read said that when leaf tips curl up its a nutrient deficiency but im scared to add anything since i havent even checked the ppm's yet...

 

[kctats13]

Heres a pic of the room theyre in. the only difference is i got rid of all those extra clones that are sitting on the containers.
the room is 5' x 9'

 

[jmansweed]

Kind of looks like K def. to me - but thats a guess. Potassium can be unavailable in high ppm water - is that what your thinking?

 

[kctats13]

I was thinking just since the ppms probobly aren't right so its causing nute burn.
Is there any type of nutes I can use that are well balanced so that I wouldn't have to worry about any deficiencies?

 

[dman1234]

have you tried giving them some Cal Mag, the leaf tips are shark toothing
witch can mean they need Cal-mag

 

[legalize_freedom]

I agree with cal-mag, or some trace minerals...usually if on of the trace minerals is deficient, others will be...or will be soon. I'm no hydro grower though, so you may want to go with their recomendations of how to fix it. Good Luck!