Light burn rockwool cubes in veg

Alright after a successful build and alot of error along the way I am out of solutions for the problem I am experiencing could really use some input as it has became very frustrating.

I am experiencing light burn with every batch I try to get rooting into my.rockwool cubes before introducing into a top feed 5gallon bucket drip recirculating system using 6" net pots and black lava rock

Room 12x12' 8 feet high
6x1000w MH hortilux blue bulbs
18/6 light schedule
Blue ox Co2 generator with grozone controller
Drieaz 1200 dehumidifier
Can100 with 10" fan
3 fan keeprite chiller with solenoid + ECT
bluelab guardian meter
55gallon barrel with stainless steel immersion coil as water chiller
Carbon filter on city water with very low ppm and no chloramine( I let water sit aswell just in case to let evaporate out of Barrell prior to using)

So receiving my clones in peat pucks and transplanting into rockwool cubes . Soak rockwool for a few hours at 5.5ph with a ppm of 360 using gh nutrients 1/1/1 ratio adding pottasium silicate first then my micro,grow,bloom, cal mag and advanced nutrients voodoo juice for a root developer.

I am currently running hortilix blue MH 1000W and keep the babies a fair bit out of the direct light and introduce it over about a 5 day period until directly underneath 1000w to reduce the shock as they were previously underneath t5s

Room temp never above 80 farenheight
Water temp 65
Humidity between 70-75% for early vegative stage
C02 at 400ppm propane generated
Nutrient ppm in rockwool 360ppm
Continue future feeding at ph 6.1 range

I have attached a photo.below of the signs I am experiencing running nukem strain in first week.after introduced into grodan rockwool.cubes.

I have danced around thinking it is a.nutrient defincie or over feeding and have tried feed feed water and nothing seems to help. I strongly believe it is not and that it is simply light burn from trying to start my veg under these powerful 1000w bulbs. I really need input before I do anything drastic and either replace all my bulbs or change to 600watt ballasts or simply rip everything out and go to soil as this is my first time trying hydroponics.

Hope to get some input here thanks again.

My clone/seedling table currently uses 400 watts CMH with 300 watt draw LED side lights.
Previously the table has used 600 watts HID with 316 watts T5 plus 200 watts LED.
Meters are used to set the light levels and the larger lights give a more even illumination with less light fall off with distance.

Clones get 100 to 120 umol until roots are good.
Seedling and rooted clones get 200-250 umol.
Plants over a foot high get 500 to 700 umol.
Mature and budding plants get 800 to 1100 umol depending on strain and spectrum of light mix.

The actual physical wattage of the bulbs does not matter as long as the intensity on the plants is correct and the spectrum is close.

Quantum flux meters in the PAR spectrum run $200 to $300 dollars, less than the value of a single plant. Well worth the investment. Color meters will give a further breakdown of the spectrum but are a luxury, the PAR meter is a must for keeping up with the learning curve.

PS: Total wattage is 7000 for the gardening area, but do not have any bulbs over 600 watts, most bulbs used are 400 watts and the LEDs are in the 300 watt range. For my gardening style these sizes came up most efficient. If I had more ceiling space then 1000's would be used.

PPS: EC is used but the equivalent ppm would be in the 600 to 800 range, less when in veg tends to start yellowing between the veins on some strains, although most are fine.

Okay that sounds good so i shall go invest in a good light meter that measures PAR before I do anything drastic thanks alot for the advice and i aswell increase my EC ppm up to the 600 range

You should start your cubes with an EC of 1.5 minimum, really start with 2.0 . And that is NOT light burn. Looks more like underfeeding mixed with a pH issue. Your feed should be 5.8 pH going in. There is also no reason to do 18/6, just do 24 in veg. And you should never do a recirculating system with rockwool, drain to waste. Soak em and dont water until they are light. Net pots in a five gal should be reserved for dwc. Always drain to waste in rockwool, thats why you are seeing issues

We go from a single t5 over clone trays to directly under 1k gavitas and 630 CMH with rockwool charged with 2.0 EC

High Grade Only said:

You should start your cubes with an EC of 1.5 minimum, really start with 2.0 . And that is NOT light burn. Looks more like underfeeding mixed with a pH issue. Your feed should be 5.8 pH going in. There is also no reason to do 18/6, just do 24 in veg. And you should never do a recirculating system with rockwool, drain to waste. Soak em and dont water until they are light. Net pots in a five gal should be reserved for dwc. Always drain to waste in rockwool, thats why you are seeing issues

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NFT is a recirculating system and uses rockwool... I've used this style of growing for 15 years with no problems...

What nutrients are you using @westcoasthydro?

Nft is the laziest system ever. It works , sure, but you are not using the block how it was intended. You are not controlling dry down rates or crop steering with irrigation strategies . Recirculating nutes, especially after they have past through rockwool is not ideal. Sure, it works, you can also grow a plant with miracle grow, i dont personally recomend it though

Lets see the pics of your nft system functioning so well..... 15 years huh? Dont you know the rules..... pics or it didnt happen bro. Please show me, and the rest of us, pics of your NFT system pumping out the great results you speak of.

Definitely looks more like nutrient burn or ph issue rather than light burn. Flush them good then double check ph and feed light.

As you're so experienced you should know that the nutes don't actually pass through the rockwool.. The nutes flow through the channels and the rockwool sits above these channels on a spreader Matt.. NFT is a proven system that has been around for years, it works on a small scale as well as a commercial scale..

High Grade Only said:

Lets see the pics of your nft system functioning so well..... 15 years huh? Dont you know the rules..... pics or it didnt happen bro. Please show me, and the rest of us, pics of your NFT system pumping out the great results you speak of.

Click to expand...

Your so right, it's never happened, never grown a single plant in my life, not got a clue what I'm talking about..

I have nothing to prove to you sir, you carry on advising people to start at 2.0ec it's actually laughable!!

Skunkpassion said:

Your so right, it's never happened, never grown a single plant in my life, not got a clue what I'm talking about..

I have nothing to prove to you sir, you carry on advising people to start at 2.0ec it's actually laughable!!

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I have pics to back up my claims. You are chilling on your moms couch trolling a forum. All you would have to do is some research. We run a legal, permitted facility with agricultural practices put in place from years of research, and personally get consulted by reps from grodan, entymologists from UC's and organic chemists. But im sure you know what you are talking about

High Grade Only,

Do you still defoliate during flower? Been following your threads for a few years. Love the show.

Listen to HGO. Your problem is from nutrient strength being way too low for a 1k light. As soon as my clones root I hit them with 2.0 EC, vegging under T5s.

Also...

Keep your RH under 70%
Pump your CO2 @ 1000 - 1500ppm
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High Grade Only said:

You should start your cubes with an EC of 1.5 minimum, really start with 2.0 . And that is NOT light burn. Looks more like underfeeding mixed with a pH issue. Your feed should be 5.8 pH going in. There is also no reason to do 18/6, just do 24 in veg. And you should never do a recirculating system with rockwool, drain to waste. Soak em and dont water until they are light. Net pots in a five gal should be reserved for dwc. Always drain to waste in rockwool, thats why you are seeing issues

Click to expand...

Just do what this guy says. if you need to validate random internet dude giving recommendations or why this random internet dude is co-signing him go look at High Grade's journal. You are going to be hard-pressed to find someone with picture validation of a setup that indicates they know rockwoll better than this guy.