Lower Leaves Yellowing and turning brown

[tcruse11]

I'm in my fourth week of my grow. The bottom leaves are turning yellow then browning. Here's a little info on my set up

Ebb & flow system- watering 3x daily for fifteen minutes

600W MH in a cooltube

80 degrees F

Humidity is 45%

5.9 PH

565 ppm (with a .5 conversion factor) which gives and EC of 1.13

Just did a water change yesterday. I'm using canna aqua, cannazym, & rhizotonic

[tcruse11]

bump!

[Help_Needed]

Originally Posted by tcruse11

600W MH in a cooltube .... 565 ppm (with a .5 conversion factor) which gives and EC of 1.13

There's your problem. The plants are hungry. Under an HID you probably want to shoot for somewhere in the neighborhood of 950ppm.

Gradually raise your nute concentration by 100ppm per day until you JUST start to see the tips of your leaves burn, then back it off by 50ppm.

[tcruse11]

Originally Posted by Help_Needed

There's your problem. The plants are hungry. Under an HID you probably want to shoot for somewhere in the neighborhood of 950ppm.

Gradually raise your nute concentration by 100ppm per day until you JUST start to see the tips of your leaves burn, then back it off by 50ppm.

That high? Canna says I should have an EC of 1.0 - 1.2. 950 ppm would give me an EC 1.9

Is that right?

[Help_Needed]

Originally Posted by tcruse11

That high? Canna says I should have an EC of 1.0 - 1.2. 950 ppm would give me an EC 1.9

Is that right?

You're growing under a very bright light, and the plants are trying to take advantage of that, but they're running out of food. Looking at the leaves you've got both magnesium and potassium deficiencies. Normally I'd suspect pH problems, but you're pH is fine at 5.9 so the next option is your nutes are too weak.

I'm running at 1350ppm @0.7 (which is about 950 @ 0.5) *but* that's with GH products. I can't imagine that Canna could be THAT much more concentrated, though, so I'm guessing you should be somewhere in the same neighborhood.

But like I said, increase the nutes gradually and let the plants tell you when to back off.