First Grow , yellow on leaves

[newbiegrow999]

Hey Guys,

this is my first grow, 19 plants under 4 x 600w. I grow in rockwool , all plants are white widow. Temps is around 29 degrees under the lights on, humidity 40-60% .They are now 3 weeks old and I think they're doing ok. I just noticed algae on the rockwool so i cover the top, I red it should be ok within a few days. Also I noticed 3-4 plants got some yellow on leaves, i read it could be so many different things so I'm posting the pics and hopefully someone can tell me what it is.
Thanks a lot for the help

 

[newbiegrow999]

The picture number 6 is different as the others..i thought it might be nute burn but that pic worries me like could it be spider mites?

 

[navyfighter04]

Hey bud... Use H2O2 in your res. Tank.. it will take the mold away from the rockwool. Are you running a hydro system with rockwool cubes in a pot that drain? I can't really tell in your pic?

 

[prosperian]

Hey bud... Use H2O2 in your res. Tank.. it will take the mold away from the rockwool. Are you running a hydro system with rockwool cubes in a pot that drain? I can't really tell in your pic?

Say bro, great to see you're back on riu. Bak and I were just talking about you this week. email box is full. PM when you get a minute.

 

[newbiegrow999]

Hey bud... Use H2O2 in your res. Tank.. it will take the mold away from the rockwool. Are you running a hydro system with rockwool cubes in a pot that drain? I can't really tell in your pic?

hi, no i could not set up a hydro system so i just got pots that drain with the plate at bottom that keeps the runoff water till its dry. For the algae I covered the top of the pots with black plastic, is it because of the algae that i go those yellow spots on the leaves?
i got 2-3 plants that have yellow on top of leaves so i think thats nute burn. Im flushing a bit now for a day or 2.

 

[newbiegrow999]

also what concentration of h202 should I use ?

 

[*BUDS]

Too hot ,every degree above 26 affects the plant. Turn one 600 off to get it to 26.