Yellow brown spots on leaves...

This is a shot I took two days ago of a plant. Upon a friend's recommendation, I ceased using my nute program and dumped my solution entirely, using only water and hygrozyme, ph'ed to 5.7. Now, some more spots started appearing on one of the newer leaves yesterday, just isn't as full-spread as this one was (this is on the first true set of leaves).

I'll try and give as much info as possible. Room is kept 74-77 degrees at all times, plenty of air circulation, humidity is 55-59%. Light is a 400 watt MH that is approximately 14" from the plants. Last nute mix they got was 2 mL Micro, 4 mL Bloom, 3 mL Cal-Mag, 8 mL Liquid Karma, 6 mL Hygrozyme, and 5 mL Sweet - all in per gallon values. I realized now I should stop using Cal Mag for the time being and reduce my value by half for LK, which I was planning on doing with the next rez change in 2 days.

Yesterday I noticed the same spots on a newer leaf (same plant) even after I had changed out the water, and also noticed the spots forming on another plant that was still in nute solution. So I dumped that one last night and mixed up 8 mL/ga Hygrozyme and water. Leaves still look worse this morning. Any idea on what is causing this? Incidentally, I have some (sometimes only 1-2) of these spots on 4 out of 8 plants...Should I just assume all will turn like this, and start them on a diet of only pH'ed water for the next week?

I'm also having the hardest time keeping my pH in check on these two buckets with only water and hygrozyme. In 8 hours, it goes from 5.7 to 7.5, and there's no way I can be adjusting more frequently than that to keep it in 5.7-6.2 range.

Liquid I had the same problem with my well water and you can't stay ahead of it--don't know but there are alkalines etc that will keep your ph from staying stable. RO water solved my problem and believe me I tried EVERYTHING before I started using it. Distilled water will work too and I know there are others out there with other suggestions for pure water. You can keep fighting it but I think you're going to have to go that route. Solved my problem 100% and not only do my plants love it my tropical fish do too. Also I would wonder if your light is a little too close for that young age--I'd have it more like two feet for awhile.

I guess an even worse problem is I'm already using distilled water. I think I've pinpointed this as a Calcium deficiecny, which would possibly make sense as I decreased my amount of Cal-Mag that I used in the reservior this week to be more in line with the micro and bloom I was adding (I thought too much Mg would cause an N lockous). I'm going to change the resevoir tomorrow and hit with same nute formula, except 6 mL/ga of Cal-Mag instead of 4. Either that or leave the mixture in the rest of the buckets, go back to my previous mix in the two I had already dumped, and foliar feed with Cal-Mag. I don't think the light is too close to the plants, though they are in the younger stage, I've been hitting them with light 24/7, so they are already 8-10" tall. I'm only using a 400 watt MH, and it's 14" from the tallest plant at the moment. I'll keep this updated for anyone who cares. Thanks!

I'm always very paranoid of light burn--it seems like sunburn in that it always seems to show up later instead of right away. If I drop water on on of my leaves and it burns the leaf the burn wont start showing up until the next day unless your light is sitting on your plants. I use 50-50 Cal Mag and nutes all the way through my grow and the one time I lowered the cal mag I noticed a deficiency within 24 hrs (green veins, yellow leaves) that disappeared with 24 hours after I readjusted the dose back to 50-50. Good luck...

PS It won't hurt your plant to raise the light and may very well help. Your ph is rising for a reason if you're already using distilled water. Have you been raising your light in line with the growing? I'm throwing everything out here...

Looks to me like an iron deficiency, and i second the notion to raise the light a bit.....

-good luck:thumbsup:

Maybe a magnesium defincency ?
check here see what your leaves look like. http://greenmanspage.com/guides/plant_abuse.html

Hi Liquid,Have you been misting them when the lights are on i had similar spots on some of my leaves.Am not sure but i think the light was being magnified through the drops of water and burning the leaves so i just started to mist the plants 5 minutes before lights out and they have recovered all new growth is now a lush green.Hope this is of some help.

Take it easy

I had a simular problem. Not saying it will solve but at that stage I had my 400w MH lamp about 20"-22" from the tops of the plants. 14" seems a bit close.

indeed Floyd, I am going through the same. GL

Luquid,

I have suffered and am suffering from the same problem. From what I understand this is a PH issue due to high PH. I have not found a great deal of people that have the same problems are pictures to match. I *have* had a lot of people shouting it's 'this defficiency' or 'that defitiency'. While it is those deficiencies, it's due to nute lockout at high PH levels.

I've learned to keep the PH down at 5.2-5.5 to avoid this problem.

If you have early plants, there is less PH buffer in the solution so it will rise much faster.

Also, keep in mind that even though you may have changed the solution and fiexed the problem, you will see the after effects for a long time.

I'm absolutely amazed at how few people have this problem. It seems that if I let the PH get about 5.8 over night, I get the spots on my leaves. I'm still suffering the consequences.