What causes the leafs to turn yellow in the center?

[Optiquest]

I am growing with aeroponics and I noticed lately that some of my plants seem to be getting a light green/yellow in the middle and that the new growth is coming in all light green. There are no spots on the leaves and other than being light green/yellow seem to be doing ok. These plants are in veg mode with a 20/4 light cycle and two 600 MH lights over them. The room temp is a bit high at 88 degrees. The plants are approx 14 inches tall. I am using "Dutch Master" nutes and change it once a week. I have never flushed the system. I keep the The PH level at 5.8. I have attached a couple of pics.

 

[Mutt]

Moved this over to the sick plants section. I would offer some help until you said Aero. There are a couple here that can help you out. good luck.

 

[Optiquest]

Thanks Mutt, I appreciate it.

 

[guru_gil]

Dutch Master rated very poorly in a recent nute test, I only use Penetrator and Reverse if needed, Wet Betty costs less and works as well. Yellowing appears to be nitrogen deficiency, I would also suspect inadequate levels of Cal-Mag-Iron if you use Dutch Master. If you have had great success with this line for a long time then by all means do as you will, but I have heard nothing good about DM except for their Penetrator and even that has lots of stories of leaf burn.
Guru_Gil

 

[Mr.Wakenbake]

Looks like you got a Magnesium defficiency or an iron def to me.... I would check the pH man ...i bet somethings wrong there.

If the pH is fine then give them a nice spritzing of epsom salts. Normally the leaves will yellow and the veins will remain green if it's Mg def.

Fast growing plants tend to do that... Mg is used extensively throughout the grow in larger amounts than any other micronute cept calcium.

Edit- another culprit can be iron.

 

[THCskunk]

That is an interesting strain? looks sativa, but what strain is it. It looks hawaiian, if it is, nice looking plant! all of what everyone wrote is true if it was another plant. That is normal for it to do that if it is the strain I think it is. becuase when lack of nitro or mag is in play, yellow begins at the tips to the node which cells reverse in flow towards the top. but your yellow begins at the nodes. Its the strain man. what it is. I like your plants man.

 

[Mr.Wakenbake]

I am sorry i don't agree ...
maybe we'll get some hydro experts in here

 

[guru_gil]

N deficiency typically shows itself (in the yellowing area of N defficiency) not at nodes as stated. N is needed during growth and even in blooming. Leaves yellow (and other problems occur) in N defficiency, first by yellowing near the bottom of the plants, lower leaves. N is a mobile nutrient. The plant will move it to the growing areas at the top of the plant (which need it more) and the lack of N in the plant overall can be seen by a yellowing of the leaves at the bottom of the plant first. This has *nothing* to do with strains, or if its a sativa, indica or ruderalis. N works the same way (or a deficiency of N is displayed - in one way - by the lower leaves turning yellow. Nodes may turn yellow eventually, if the N is really low, eventually the whole plant will weaken and die. I hope this clears up this misunderstanding.
Oh, and of course Ph has everything to do with plants ability to uptake N and every other nute.
Guru_Gil

 

[AlienBait]

It really looks like Iron deficiency. It is yellowing on the new growth and has the yellow leaves with green veins (like Mg), but it starts from the stem and works its way to the tips. Mg def, goes the other way.

Your PH is fine, so the iron isn't getting locked out. Hmmm....

Check the iron content in your nutes.

Also, Iron reacts with potassium, so if you are heavy on potassium, that could show up as an iron def (or so I've read).