First time hydro grower, starting to wildly guess, please help my babies!

3 week old Northern Lights

Ebb and Flow system

400w MH, 18-20 inches away

75F temp, 55% humidity, constant light breeze from fan

week 1

300ppm General Hydroponics MaxiGro, flooding once per day


week 2


800ppm MaxiGro, flooding twice per day, started to see tip burning and leaf curl
flushed with 10ppm reverse osmosis water then reset nutrient to 400ppm, flooding once/day


week 3

first "3" leave leafs completely turned yellow and died (I removed)

Plants just dont look "right"

reset nutrient solution to 250ppm MaxiGro, ph 6.4, once a day flooding, with intermittent 10ppm waterings (poured into containers from above)


I thought i was over fertilizing because of burnt tips and curling, but the plants have a very light green to yellowish hue and I think now that maybe I am under fertilizing


How often should I flood? and at what ppm? Ive seen answers ranging all over the place.

In the attached pics, see how even the brand new leaves just coming out have burnt tips? also notice the upward curling on older leaves on the top plant in the first photo.

Any help/suggestions will be much appreciated, Thank You.

i dont think you can under fertilize, my guess would be nute burn. i started doing ebb and flow however i couldnt get the amount right and moved to bubble ponics i would guess on doing it 3 times from what people told me however im no expert!

PPM for Hanna Chart PPM


Seedlings, Early Sprouts 100 to 250

Early Vegging 300 to 400

Full Vegetation 450 to 700

Early Blooming 750 to 950

Full Mature Blooms 1000 to 1600

Note: EC Calculations are different, here's a conversion chart :
heres a great chart that shows how different PPM can be from meter to meter... EC is the only real universal language...

The BubbleHead Gang is always glad to help out.

you know, I think it might be heat stress. stoned, but it sounds viable. I'm turning the fan up a notch, and taking a puff by them. Maybe "goodwill" nearby will help them. ha.

Your PPM is fine. I slam plants with 2500-3000. I wouldn't hit those with over 1300. Looks like it might be more a Potassium (K) problem. I don't use Ebb n Flo but use hydroton and I keep my PH more at 5.6-5.8.