[Westcoasthydro]

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.

[Phaeton]

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.

[Westcoasthydro]

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

[High Grade Only]

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

[High Grade Only]

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

[Skunkpassion]

Originally Posted by High Grade Only

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

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?