Yellow between veins, curling leaves

Hey guys, I am a first time grower trying to find the source of some issues I am seeing in my plants.

These plants are about two months old. They were in 16oz plastic cups as seedlings, first under sunlight and then under a CFL bulb. They are now in ~5 gallon pots and under a 600w HPS. They have been in Sta-Green Moisture Max Potting Mix from the start, which contains 0.14% Nitrogen, 0.11% Phosphate, 0.08% Potash, and 0.02% Sulfur.

A couple weeks after moving them into the bigger pots and under the new light, I noticed some yellowing between the veins on some of the plants leaves. I fertilized with Miracle Grow all purpose 24-8-12 once, and with Miracle Grow all purpose 20-20-20 a few times since then, always at 1/4-1/2 strength. I have also watered once with epsom salt and sprayed with epsom salt solution a couple of times.

They have improved, but I still see some interveinal chlorosis and some curling of the leaves. From what I have read I have assumed this is a magnesium or zinc deficiency, which I have tried to correct with the fertilizer and epsom salt. I bought a PH test recently and tested my tap water, which showed slightly alkaline (7.2) but just about right with the miracle grow added.


Phew. I hope I am not overdoing this. Should I even be worried? If not, what should I do?

interveinal chlorosis. magnesium and/or zinc and/or manganese deficiency. give the ferts full strength and see if it gets better. those ferts are shitty fyi. good luck

Try the stickies at the top the forum. One of them has a bunch of good pictures of problems and how to cure them. I'm pretty sure its here but that might have been a guide by greenmans pages

Here is a link to a good plant abuse page.

http://www.greenmanspage.com/guides/plant_abuse.html

Try the stickies at the top the forum. One of them has a bunch of good pictures of problems and how to cure them. I'm pretty sure its here but that might have been a guide by greenmans pages

Here is a link to a good plant abuse page.

http://www.greenmanspage.com/guides/plant_abuse.html

Getcrunk said:

interveinal chlorosis. magnesium and/or zinc and/or manganese deficiency. give the ferts full strength and see if it gets better. those ferts are shitty fyi. good luck

Click to expand...

Right on, but seeing that only magnesium is a mobile element and the deficiency didn't start on the very top of the plant, it's a mag def.

Cal-mag, 2tbs/gal molasses every watering or epsom salt will fix this.

Thanks a ton for the replies. Magnesium deficiency is what I suspected. What's the best way to treat this? I have read that salts accumulating in the soil can cause other problems, so I'm a little nervous about watering with epsom salt solution. I have been spraying with a 1/2 tsp per quart, is that sufficient to correct this problem? I haven't gotten a soil test kit yet so I don't know what my soil ph is, but that would have to be really off to cause a mg deficiency wouldn't it?

Mag is locked out at a soil pH of 2.0-6.4, so it's not really hard even for experienced growers to have this happen.

Yeah what I forgot to say with that is make sure your pH is around 7 or a hair less. That could cause the problems just like the doc said.

it also looks like heat stress there, trying moving the light away an inch

Wow, I did not realize Mg could be locked out that easily thank you both for telling me. What I have right now is a pH test and adjuster kit for aquariums. There is a bottle of test solution, a bottle of pH up, and a bottle of pH down and the range of the test is 6.0-7.6. Is there anything useful I can do with this, either testing or adjusting, or do I need to get a soil test kit?

As for the heat, I will move the couple plants showing that curling farther away from the light, thank you.

yeah man i got nute lock early on 3 of my plants early this summer and my pH was over 6 at the time