HLG 600 @ 650 lights @ Mag deficiency

Just want some experience’s from those that run hlg 600’s and 650’s.
this is my second grow, last one being 2.5 yrs ago.
I got my HLG at start of flower on my first grow, replacing a 1500 and 2, 600 w burples, Mag problems almost imediately. This grow same problems , I moved the light around and also the wattage, for now im settled at 40” and 300watts, hlg reccomeneds 24-30 inches at 350 watts. I know these lights push the plants hard, so i am adjusting.

What heights and wattage are other people running?

Quality LEDs will definitely make the plant magnesium hungry. It’s time to start supplementing more epsom salt.


I was using epson salts at 3/4 tsp per gallon, Water only 22 days in ffof, i cranked the calmag up to 6 mil lt per gallon today, 1/2 gal per plant. 5 gal pots. im going to start ff nutes at 1/4 in a week.

Maybe move your ph to closer to 6.8 for higher magnesium uptake if you’re in soil.

But looking at those pics I’m not sure it’s magnesium. Magnesium is a mobile nutrient and you’d see it on your older growth, not newer.


Yes, i learned that yesterday, so i watered today at 6.8. was phing 6.5, low for mag. I ve looked sat some other nut def pictures, it could be calcium, so calmag should help one way or the other

1 Like

I’m not sure which lights you were using before, but 300 watts at wall from hlg 600 is going to be equivalent to probably 500-600 watts all wall from typical Amazon budget lights. Could have just been too much too quickly.

You can dim a little more to help get caught up on nutrients and then start gradually increasing. I would rather see you do that and run lower, too high and you’ll just be bouncing more light off the walls.

1 Like

This is a zinc def sample, what is your opinion?

200w at 32”

1 Like

Your lights need to be dimmed. I’ve done this countless times. Including this grow cycle. The lighting makes them use a lot of magnesium. (Not sure why) there are two solutions, one of them dimming the lighting the easiest.


Yeah, I’m adjusting now, 200w. 32”, doing some lst and a lil trim underneath

1 Like

So when can you ramp up? It’s proportional to nutes too right? Last grow I had the 650 around 400 watts but was in full nute mode. Now they didn’t like 250 so dimmed to 150. But once I added some nutes to address other issues I was able to increase back to 250.

I guess my point is exactly what you said it’s a constant process of adjust,analyze, adjust more!

1 Like

ill give them several days now, let things regulate, if leaves are looking good, ill turn light up 20 watts, im going to start the feeding cycle in a week or so, maybe sooner if anything else leaf wise shows up.

Higher Light watts may work with increasing nutes time wise,

Nice jeep by the way. Had a 2008 2dr soft top, loved driving that thing but once kids came, she sat so I sold her. Def going to pick one up once kids hit 5 or so. Such a fun ride, esp if you live in warmer climates!

Sold this one last spring also, we have a canam sxs and the Jeep did not get used, not enough time in the day to ride let alone maintain all of it.

@Covertgrower is accurate as I’ve experienced this too. Basically higher levels of light increase photosynthesis and growth rates. Plant wants to explode but can only take in so much Mg at once and mg is used for speedy growth. Deficiency is the result kinda like burning more calories than u can even take in. Back the lights off a week, give em a slow acclimation and see where u stand on intensity. My autos are doing this crazy cuz I’m in dwc at my explosive rate period so lotta leaves really fast equals some yellow ones until the dust settles and they go green.