Help diagnosing plant problem

I am pretty new to hydro. I have looked at many threads and am trying to decide what the problem is. Based on pics from other threads I am leaning towards underwatering but could use some help from more experienced growers on why the leaves are twisting and curling up along the edges.

System- ebb and flow.

Flooding - was doing every 8 hrs but plants drooped a little so cut back to every 12 hrs.

Medium- trying Sure to Grow inserts. They retain water pretty well.

Res temp 74-79

PH - 5.9. - 6.0

PPM - around 700

Light - 1000w about 4.5 feet above plants

strain - Arjans haze

Attaching pics. Thanks for any help!

Hi Pluto420,
I'm growing Arjan's Haze as well. I have it at 8 weeks of flower in soil under a 400hps and about 3 wks in veg in my new bubble set up (80 watt flouro). I trained both early on and it can really spread out. I dont know a lot of the particulars with the ebb and flow system but I will say that in the bubble set up i'm seeing a lot more puckering leaf growth like in your pics. It grows a lot wider leaf in hydro (way faster too). Looks like a different strain except I cut it from my one... I also use organic nutes so I tend to us a lower ppm closer to 300. It seems to make sense as a lot of the organic nutes are less soluble and stay suspended, except that the roots grab them and feed from them. Maybe that is part of what you're seeing. Are you vegging under your 1K? Also, from what I've seen so far it seems to like a slightly higher ph, like mid 6- I seem to recall reading that. Hopefully I'll have some pics here soon. I, we burned thru 2 cameras in less than a year I need to get a new one...anyway hope this helps, Nug

i was gonna say the same thing , try your ph at 6.4

I think it looks like it could be heat or light related issues. I am thinking the lights are too close or too intense for them. It could also be stress from the lights being too intense or if you are no consistent with the light schedule.

Thanks for the replies. Nug this is my 2nd time growing arjans #1. The first time was in soil and it came out very nice. I did see a little leaf curling but not like this time. I am starting to think both of you are right and maybe its the light. The temp is not an issue i dont think as the light is far away and the temp at the plant level is about 74. But this is my first time using a 1000w light and based on your comments and what is different this time I am thinking the light was too intense to early. I am going to try some CFL's for a few days to a week and give them a break from the 1000w.

Thanks!

Do you have a big ass fan blowing right on the part of the plant you took a picture of? I have noticed that Sativa's growin indoors don't like to be blown on very hard. The leaves start to get that curl on them.

They definitely look big enough to handle a 1000w light. Especially if it's really 4.5 ft away. If all else is well and you are still having the problem, I would dump the res and start over. Something must be a bit caddy wampus in there.

I don't know if you stated which nutrients you are using, but if your plants are so small that you even suspect the light is a problem at 4.5 ft, they are too small to be at 700ppm. I don't recall reading the age of the plants either.

Are you using RO water?

Exactly what nutrients and additives have you put in?

Edit: I looked at the pics again and 700ppm seems EXTREME. Dump your res and put your nutes at like 200ppm and leave the light up nice and high. They will be fine, it's just too strong for such a little girl.

I dont have a fan blowing on them. I have a fan circulating air but not directly on the plants. I am using Bontonicare and canna nutes. The plants are from cuttings, had deep roots before transplanting and are just over a month old.

I have drained the res and now have ph of 6.2 and ppm of 260 after adding Pure Blend grow, Thrive alive 1, sugar daddy, cal-mag, and silica blast. I am also going to keep them under cfls for a few days just to give them a break and a chance to recover.

I have a question about the res. I am using the CAP ebb and grow system which has a 55 gallon res. The instructions on the bottles say to add for example 7 ml per gallon of pure blend grow for seedlings and 15 ml for mid size vegatative per gallon. My res is filled up to the 40 gallon level. I put in about 5 -7 ml of pure blend grow and the ppm went to 200. If I was to follow the instructions on the bottle it would seem to me that I shoud be adding alot more .....40 * 5ml or 10ml. That would put my ppm into orbit. I have a Nutridip tri-meter which when i put in the testing solutions goes right to ph 7 , ph4 and ppm 1500 so I think I have the meter calibrated right. What about this am I not getting?

Thanks!!

That you can't follow the advice of the bottle. You should be just fine now. Keep your meter calibrated and you'll be in good shape. At a ppm of 260 you should be just fine.

Check your ppm in a few days. If it goes UP then your nutes are too strong. If it goes DOWN then your nutes are too weak. If it stays the same you are right on course and the plants are drinking as much water as they are taking up nutes and your are in the correct range.

Thanks for all the help. I will keep a close eye on things and keep learning.