Leaves Drying Out. Please Help :-(

As you can see from the pictues my leaves start with browning in the middle then dry out altogether ? Its happening to all 7 plants.
Ive had this exact same thing happen to me on my last 2 grows as well both at the exact same growth stage. ( Both times they pulled through though )
Ive had many successful grows previously and im stumped as to why this keeps happening.
Since i first started ive not changed anything at all including nutes room setup etc.
Fans are not blowing on the leaves to cause this either.
Any input would be greatly appreciated...

Setup is as follows..

Plants range between 6"and 9" tall
Plants are in veg
Im growing in hydro NFT system
1X 400 hps light 3ft above plants
Temp day 76 night 62
Water temp 64
Humidity 40-50 %
Using Vitalink A+B grow
Bubbler in tank for oxygen
PH is 5.8 - 6.0
Water was left for 48hrs before tank was filled
Nutes where added as bottle instructions for young veg plants


As i said any input would be greatly appreciated....

Your light is too far away from your plants. Pics of the whole plant would be better as well.

How close should the light be.
I backed it off because this was happening.
Il post plant pics now.
Thanks

A 400 watt light needs to be pretty close to the plants. I like to keep mine with-in 18 inches. What type of hood do you have for your light?

The plants look in good shape after ive took the bad leaves off but you can see the same thing happening to other leaves the same as last time , and you bet by the morning they are dried out as well

The standard large shade

The cupping on the leaves indicates it's trying to dissipate water but cant. This could be due to heat stress, salt build up. I would go 1/2 stregth nutes to start off with and then see how the plants respond to that.

I cant see it being heat stress the temp has never been over 80c
Il 1/2 strength nute them today.
Also a 400w hps 18" off the top of the plants would that not burn them cos the light gets verty hot and with the plants drying out could that not worsen the problem ?

I am not familiar with your nutrient product but it could also be a micro-nutrient deficiency. If possible/practical I would flush out your system re-fill with fresh R/O water. You said you let the water sit out is that because you are using tap water? Tap water contains minerals in it and if the minerals in your tap water combine with more minerals in your nutrients then you can begin to experience lock-out.
Also switching to an enclosed hood will allow you to get your light closer to your plants.

Ive used the same nutes in the same room with the same strain for 1 1/2 years using tap water and only ran into trouble on the last 3 grows is it possible it could be the tap water , the water is not hard where i live at all.

UPDATE.
Ive emptied the tank and refilled with 1/2 strength nutes.
Ive turned my other 400w hps on as well, so thats now 2x 400w hps 3 feet away from plants.
Temp - humidity same as before.
Also when emptying tank i noticed a very slight film on the top of the water what could that be.
I gave the tank a wash out before refilling.

Check PH of tank and give a clean out make sure you drop down nute feed to half and then refill. I dont use hydro but if i did then i would keep my tank covered also bro. Not sure if it helps but gd luck

Bump bump

Any more advice would be great

to be really honest, i also think the light is way too far away. I have a 600 hps and I am a foot of less away from my ladies. All you need to do is have proper ventilation and circulation in your room and there is not issue. My hood is super old and has not air cooling holes, i just point fans at it and over the tops of the plants. You will see a much higher quality product with more weight, density and potency with the light as close as possible. And a burn from a light will be a brown yellow blemish on the leaf, looking like a scar. this is definitely not due to the light.

Now with the leaf issue, I agree with the lowering of the nutrients. Less is more...more often than not. Make sure your pH is proper all the time and thats all i can offer you. peace

and you don't filter your water??? Definitely something i believe in...unless you have a high quality water source. I work in the water business. So i know what I am talking about here. Do you have any staining on any of your fixtures, shower doors, toilet bowls/basins, sinks? I suggest RO filtration, but is not always necessary. I also suggest a TDS meter at least to make sure there is not an obscene ammout of nutrients in your water. For hydro I have heard never go over 1600-1800ppm but ask a hydro grower, and you need to check EC too in hydro.

Update.
Ive noticed ive got thrips, surely they couldnt do this much damage though.
Ive since sprayed to kill them.
Also noticed a very slight film on the water in the tank, what could that be ??
Any more thoughts Please....
Light , airflow, temp , nutes, ph, everything as it should be....

OMG STEVEOO
bump for more answers, i am in my first grow and the same problem is spreading up my leaves, its progessively jumped upp each set of fan leaf, from node 1 to node 7, after completely wilting them and falling off with a poke.
i am in soil tho, it almsot seems to me like its a form of mould growth, do you have proper ventilation? becasue i dont, and ive based it down to that. ive been told to give a good flush and trim the effected areas.
your thoughts??

My ventilation is perfect.
My problem affects random leaves though is does not progress up the plant.
Ive been told by my local hydro shop to add rhizotonic which is a root growth stimulant to make roots stronger so the plant can overcome it quickly.
Its happened on my last 2 grows and the plants kind of grew out of it but it still gives you a big scare and makes you wonder what is going wrong..