Plant leaves turning yellow. Help!

Hey guys, Im pretty new. I read alot of post and come often for updates. Well I have been growing 2 plants in a home made hydroponic recirculating system for nearly a month. I started with 3 but one had mites so we booted it quickly. It was a free clone so we figured it had issues from the start, it never really grew like the other two.

Okay so I have a watering schedule of 15 minutes every 3 hours, we felt we watered too much in the begining, so we changed from 15/45 to 15/3hrs <- ... Our lighting schedule is at 18 hours from 6am-12am. We started using nutrients in the water bloom, micro and grow at 5ml per gallon of water. We currently have 10 gallons. We expected 5 more plants to come, but they dies during rooting... Anyways one of the plants began to yellow on the leaves and I did research to see it was possibly chlorophil after ruling out nute burn and over watering and root rot. The leaves were quickly turning yellow and curling up.

I read this was a mag problem so I purchased some espon salt and added 1/2 a tsp for every gallon. This seemed to do the trick.

after a few days tho, and a clean water change plus an upgrade in nutrients 12ml 7ml and 2 ml per gallon, the plants are turning yellow again!!

Did I over do it with the nutes? Should I add more epson salt? We're so close to the next stage in growing and dont want to lose our 5th plants!! We keep a steady eye on the plants daily and write in a journal.

We need help... Photos attached... due to the lighting.. you cant really see the true color, but you can tell its fading... the leaves are light green, some are dark, and turning yellow and crusting and turning up!!

EEEEKKK HELP!!!!!

how hot and how close are your lights. im new as well but it looks like a combo of heat stress and nute burn bad.

what is the ph? and what is it doing? in the mean time get some regular old 20/ 20/ 20 plant food for soil and foilar feed them until you get this resolved.

but i could be very wrong just trying to help ya out

you plants are maby stressed out you should only have the lights 16 hr a day i had the same problem ad some b1 for the stress of the plant.

It looks like you are lacking in nitrogen. What kind of nutes are you using and are you following the feeding schedule that it recommends. I grow hydro and have never had a nitrogen problem. Need a little more info on your setup, how you are mixing and do you have a good grow book?

jorgealopez707 said:

you plants are maby stressed out you should only have the lights 16 hr a day i had the same problem ad some b1 for the stress of the plant.

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wow...help me out with this 16 hr of light thing???

The whole light thing depends on who you ask. Some people veg for 24,18,17,16, 12/12 whatever. I have read in several grow books that the plants do not use anymore than 17 or 18 hrs of light the rest is just wasted money. Don't know I veg for 17 hrs and I have used 24 before, in fact my clones are 24 right now but I think my plants do better with 17 verses 24. Think about how long the day is during the middle of the summer? Depending where you are at, it's probably around 17 or 18. In the fall as the days grow shorter it is usually around 12 hours of day light. See the pattern? What kind of system do you have? Ebb and flow, aeroponics, deep water culture?

i veg for 12 on 5.5 off 1 on and 5.5 off. the article i read says thats all you need and its in every horticulture textbook. and its supposed to make them grow quick

Tommythecat14 said:

The whole light thing depends on who you ask. Some people veg for 24,18,17,16, 12/12 whatever. I have read in several grow books that the plants do not use anymore than 17 or 18 hrs of light the rest is just wasted money. Don't know I veg for 17 hrs and I have used 24 before, in fact my clones are 24 right now but I think my plants do better with 17 verses 24. Think about how long the day is during the middle of the summer? Depending where you are at, it's probably around 17 or 18. In the fall as the days grow shorter it is usually around 12 hours of day light. See the pattern? What kind of system do you have? Ebb and flow, aeroponics, deep water culture?

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Can you provide any references of these books? I would like to do more research on this topic. I don't see how it can be wasted energy if the light is creating photosynthesis. Not saying either is right or wrong I would like to see how they describe it.

statictree said:

how hot and how close are your lights. im new as well but it looks like a combo of heat stress and nute burn bad.

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Well its in the closet and the watts are currently at 400... I started at 300 then moved up to 400, I have a 600 watt light, but it gets very hot in the closet. We leave the door cracked and make sure the temp isnt too hot during lighting schedule. The light is pretty close, around 10 -12 inches from the plant.


For my nutes, im using, general hydroponics micro, grow, and bloom. I started with 5ml of each per gallon and recently upgraded to the next stage becuase I thought it was ready, maybe I shouldnt have done that.

We built a system that has sprayers that go off every 3 hours for 15 minutes, the resevoir holds the nutes and water and basically recirculates with help from the water pump. We have an airstone and fan working 24/7. The ph is at 6.0 currently. Our water is very high in acid ( dark green) so we usually take it down with Ph down via general hydroponics.

What horrible things am I doing wrong to make my beauties begin to fade on me? Is it a nute lock out? Is it nute burn? Its like, you just have to keep figuring it out... Im glad I've had the opportunity to make a sick plant become healty, I just hate the extra time and maintenance and cost to fix a sick plant. i dont wnat to let thee two grow as this has been the biggest investment so far...

You've got several deficiencies going on there. Predominately micronutes. They're very hungry. GH nutes work best with a 3-2-1 ratio for veg, 1-2-3 for flower. Look on the bottle, that's what the manufacturer calls for. Stick to it. For aero, 50% strength should work well. Feed more frequently for shorter duration. Try 5 minute spray every hour. As long as you don't have standing water in the tubes, it's actually very hard to overwater in aero. Underwater (roots drying out) is more likely.
You say it gets very hot in there. How hot? Get to the nearest Walmart and get a garden thermometer/humidistat with memory. Costs about $12. You can't control temps and humidity if you don't know what they are, especially during lights off.
They look a little heat stressed from the light being too close. 10-12in is okay with an aircooled light. If not 18-20 is better. Hold your hand under the light, palm down. If it's uncomfortable for your hand, it's uncomfortable for the plant. Sounds simple, but you'd be surprised how many people burn em up this way.
You're pH seems a bit high. pH for hydro should be 5.5-5.8. Don't get too anal about it though. Set it at 5.5 and let it drift to 6.0, then reset. Wider availability of nutes that way. In the end, pH may be your biggest problem right now. Some nutes are locked out at high pH, particularly some micros.
You kinda chose a Ferrari for your first car, but if you take care of these simple things and get the temps under control, you should be fine.
Hope this helps,
Fred