My second grow, might need some advice

Thread starter #1
Hello there!

This is my second grow. My first with only auto strains, 2 Think Different and 1 Automazar. I´m using a DR60 with a 250w HPS.
I planted the seeds in soil 17. August, so they are about a month old now.
I´m using Plagron Bat Mix with 30% extra added perlite for 2 of the plants. And then i have one TD in Plagron Light Mix. 11L pots (3gal).

So, to my problem. When the plants were a few days old, i managed to drop my PH meter to the floor, the glass bulb thingy broke, so i had to order a new one which i didn´t get before last week. But in the meantime i had to water my plants without checking the PH, my tap water is 7.0. And last week when i got my new PH meter, i regulated the PH to 6.4 and watered them with that. And now, some of the leaves on the plants in Bat Mix are starting to get yellow spots.
I have been searching around, but damn, it´s too much information out there....
This is PH fluctuation, right? Or do you think it´s something else? I know one of them is a little heat stressed, but i don´t think that can cause the yellow spots

Bad photos, i know. I can take some new ones when the lights are off tonight



 
Thread starter #5
The light is 30cm from the tops (12 inches)
I just learned that heat stress actually can cause yellow / brown spots, the leaves are slightly curling upwards as well, and the spots are only at the top leaves. Seems like everything is pointing towards heat stress after all. I will try and raise the lamp a little more.
Thanks a lot by the way, i´m still new in this game, so mistakes will be made.
 

Antics

420 Member
That distance isn't too bad for a 250w HPS. But that particular strain might prefer a slightly cooler temperature. Every strain has different tolerances, and even further, different phenotypes of the same strain can have varied tolerances for heat, moisture, nutrients, etc...

From this: http://www.420magazine.com/forums/h...-what-distance-should-my-light-my-plants.html I'm seeing 30cm/12" is acceptable for a 400w HPS. So We can try to leave the light where it is, and see if you can improve ventilation.

You're welcome. I like posting in these topics to help folks out with problems so I can learn myself. I'm only on my 3rd grow now lol. So you are going to learn A LOT as time goes on.
 
Thread starter #7
I´m actually waiting for new exhaust fan as we speak, the one i have is supposed to be strong enough for my tent size. But it´s a cheap crap fan, unbelievable loud. Sounds like a vacuum cleaner is running in the room. The new one is much stronger and still more quiet.
So the ventilation will be improved, perhaps that will do the trick :)
 
I think you where right with your diagnosis. You should have slowly brought PH'd water down a couple points at a time as opposed to a complete leap. I am not a 100% but it does look like PH stress IMO.