Crispy brown leaves!!!

My problem.... Growing 30 plants under (2) 1000x HPS. They are now 26 days into flowering and 4 feet tall. Their growin strong with wonderful bud sites but about a week ago a few plants' leaves started turning brown and yellow at the tips. Lights are 3 feet away, plenty of air circulation and I feed every two days with 50-50-17 root and bloom(only half a teaspoon per gallon.) I also noticed fungas gnats around same time? Could they be the problem with the root damage that has occured? I went and got Gnatrol and i'm on my second day of treatment. Any help would be greatly appreciated fellas!!!!!

Almost forgot. They are not a soft and pliable. They are crunchy with upturned leaf tips.

I`d say you`re over feeding em
Full strength every 4 day`s is quite a bit...flush a couple times, then leave more time between feedings...7 or 8 days.50-50-17 is the wrong ferts for flowering ..you want a fert with a higher middle # something that reads like 10-52-10. The 1st number is for nitrogen plants don`t need alot of that in flower.
Diamatious [sp] earth will help with the gnats, sprinkle some in the top layer of your soil, it`s like glass to them...they crawl on it, get all cut to shit and bleed out and die...lol you may have to use it a couple of times, that along with sticky`s work great.
hope this helps ya some.
canadiancowboy

im getting yellowing and brown uptuned crunchies 2!!! 1 week into flower think mine was due to over watering?

Hi!

Far away beeing an expert i read the grow faq and lot of threads concerning ferts for flowering, it recommends higher potash.
I would like to quote the widowman: "hi nutes for flowering (mid august ,times depend where you live) n6/ph10/po15 potash for buds ,phosphorus for strong roots and nitrogen for stem and leaf growth"


Peace, Martin

You are over feeding the plant! The change in color on your plant is an direct effect of to much nitrogen.

sounds like your overfeeding the plant

this happens to me at 3 weeks in flower almost every time.

i'll lose about 25% of the fan leaves, like clockwork.
they turn yellow then brown then gone.

its all cool after that.
new growth is fine, and my light pennitration is greatly improved.

the end result is just fine too, and soo sweet.

btw i use the foxfarm line at 3/4 strength and 2 400w hps

good luck with your gnats

diatomatious earth didnt work for me(heard it was more for ants)
Go-gnats didnt help much either.

i may be using them wrong,
let me know if you find something good cause i need help too.

Ok...Newbie here too. I have two Sensi-Stars in a 2x4x6 HydroHut under 600w HPS. Budding is amazing, but like others, Leaves are yellowing; turning brown and drying out. I use the Foxfarm line along with their feeding guidelines from their website and was feeding with every other watering, then cut back to feeding every third watering. Still have a problem. Light too strong? Has anyone ever suspended shade cloth between the light and the plant?

shade cloth?

more light the better(hps) as long as its not too hot.

stinkincatfish said:

shade cloth?

more light the better(hps) as long as its not too hot.

Click to expand...

Thanks, stinkin...and that's what I thought but I've tried everything else! I've cut back on the feeding and that didn't seem to help...I'm diligent about checking the pH of the Distilled Water I'm using...I don't let the girls sit in water, I pour it off...perhaps I should cut back to 400w instead of 600w?

RiverCityGuy said:

Thanks, stinkin...and that's what I thought but I've tried everything else! I've cut back on the feeding and that didn't seem to help...I'm diligent about checking the pH of the Distilled Water I'm using...I don't let the girls sit in water, I pour it off...perhaps I should cut back to 400w instead of 600w?

Click to expand...

Interesting. I also use a 2x4x6 Hydrohut and am right at week 4 in flowering. I am getting some yellowing/browning of the oldest leaves on my plants, as well. Sometimes I think that my hut is too small for the 600w hps light that I use, although the temps at canopy height are not too high (highest it ever gets is 85 and that is rare), but it justs seems like the light is maybe too intense for the plants. I know 75w per square foot is supposed to be ideal, and 75x8=600 (the sq footage of the HH base is 8 ft), so it seems like 600 should be perfect...but sometimes I think it may just be too much for an HPS light in that size hut without a lot of area to dissipate the heat and circulate air, even with a good exhaust fan, which I have (Vortex 6")...I definitely notice the plants directly under my light are a little "bleached" compared to those on the perimeter. Keep in mind, I have no air conditioning...so whatever the air temp outside is, that is what I have to work with. I have a feeling that if I could regulate my air temp at a nice and cool level during the light cycle, then everything would be okay. It is pretty much always 70-75 here during the day and cool at night, but the 70-75 day temps are a little high for fresh air intake. Overall, things seem to work out well. But I do agree with you that the 2x4 hut may be small for a 600w. I would be REALLY interested to see the results of a 400w in one, in terms of heat/humidity/yield...