Yellow/Brown Spots, Curling of Leaves

Hello all... This is my first hydro grow, second grow ever. Currently have Euphoria in veg started from seed, about 3.5 weeks old.

Main symptoms: brown tips on older leaves, a bit of brown spots on half the leaves. A bit of yellow spots as well... The leaves also seem to be almost curling upwards. At first glance she looks healthy, but I'm growing concerned... Could this be magnesium deficiency? Should I add epsom salt?



^ I am not too concerned about this leaf because it is one of the oldest but here's the damage that's most visible. It might've been nute burned when it was too young.






Leaves in general look a bit off, curling slightly upwards (esp new leaves). The old leaves (top and bottom) aren't very uniform and are curled downwards.

On the right leaf, there is a small visible yellowish spot. My cam sucks but there are little yellow spots on half the leaves, and the green in some looks "mottled". Hard to explain.


HYDROPONICS DWC

How long has this problem been going on? Almost since transplanting into hydro
Are you growing in a PVC grow tent? No, attic
What STRAIN are you growing? Euphoria by Dutch Passions I think
What was the establishing technique? Seed
What is the age of your plants? 3.5 weeks
How long have they been in there mixture they are in now?(coco,soiless etc..) 3 weeks
How tall are the plants? About 4-5"
What PHASE are the plants in? Veg
What substrate/medium are you using? (Hydroton, RockWool etc.) Rockwool surrounded by hydroton
What is the Water temperature? About 85 F. I know this is too high but I don't know of a way of keeping it down in this heat...
What color are your roots? Mostly white/light beige-ish.. No slime
What Nutrient's are you using? Fox Farm grow big and big bloom, for now.. Although I have the soil version of grow big, a previous grower said that would be fine...
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful* At first I might've nute burned when it was too young (about a week ago). 1st feeding: 1 tsp/gallon of Grow Big. Looked like nute burn so I flushed. 2nd feeding: less than 1/4 tsp/gallon of Grow Big 1/2 tsp/gallon of Big Bloom.
How often are you feeding? I've only fed it twice so far, try to do it once a week after flush
How often are you giving nutrients? ^^ Not the same question as above?
What order are you mixing your nutrients? Did big bloom first then grow big.
What is the pH of the "Tank"? pH wants to stay around 6.4. Usually around 6.0-6.8; I know that's high but I don't want to overnute so I give it pH down when it needs it, have done it twice in a day before
How often are you testing your pH/PPM/EC/TDS? Test pH everyday, sometimes 3-4x a day. I don't yet have my ppm meter.
Are you sure your calibration is correct on your equipment? Using those liquid test drops to test pH with color codes. But it cannot tell me pH below 6.0; need to get a new tester.
When was your last watering? Changed water 3 days ago.
What size bulb are you using? Currently 2 100w CFL's (not 100w equivalent).
How old is the bulbs you are using? Brand new
What is the distance to the canopy? About 5-6 inches but there is minimal heat from the CFLs
What is your RH Factor(Relative Humidity)? Don't know; will soon get a hygrometer
What is the Day/Night Temp? (Include flucutaion range) About 78-90F, I think. Usually does not reach 90.
Tell us about your ventilation, intake exhaust and when its running and not running? I suck at hardware stuff. Have a small vent with a powerful pc fan 5" blowing out of it. Don't really have an intake though (small hole through the wall). Runs 24/7.
Is the fan blowing directly at plants? Yes
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? Tap water
If using tap water, what is the ppm/EC/TDS of the water right out of the tap? Don't know
Have any pest chemicals been used? If so, What and When? Just sprays with diluted neem oil. Used about 3-4 times, last time was 2 days ago (like to be safe).
Are plant's infected with pest's: Saw a total of two bugs during this plant's life in the hydroton. I don't know what they were but I think the neem oil took care of them.

Any help will be SORELY appreciated... I put so much time, effort, and money into this and would hate to lose her already...

Looks like you are feeding a tad too much. Back off the ferts.

I've read reports of people using full strength Fox Farm nutes from 2 weeks old... Mine are older and I'm giving it about 1/2 strength and it's still too much??

When do I know when to add more nutes?

maitai said:

I've read reports of people using full strength Fox Farm nutes from 2 weeks old... Mine are older and I'm giving it about 1/2 strength and it's still too much??

When do I know when to add more nutes?

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Whats the starting quality of your water? I stopped paying attention to bottle labels years ago and stick to my TDS/EC/pH tools. I always had problems like this when I'd rely only on recommended doses that are on labels. You can get a TDS meter for as little as $30 and pH testing kit for around $10. You see if your water is hard say 200 ppm from the start and you add your FF veg ferts to it it'll probably be higher than what the manufacturer saw. I believe FF grow big will raise ppm's by 300 per tsp. There really isn't any reason to be using the big bloom yet. I know that stuff is expensive based on how much you need to add to water to get to the desired amount. Its like a cup per gallon or something.

I have a ppm meter coming to me in the mail as we speak.
I'm trying to follow Fox Farm's hydro feeding schedule: http://www.foxfarmfertilizer.com/FoxFarm-hydro.pdf Says to use the Big Bloom from seedling. It's only about 2-3 tsp per gallon.

Hopefully when my ppm meter comes I can take care of this... But if anyone has any more insight, I'm all ears.

maitai said:

I have a ppm meter coming to me in the mail as we speak.
I'm trying to follow Fox Farm's hydro feeding schedule: http://www.foxfarmfertilizer.com/FoxFarm-hydro.pdf Says to use the Big Bloom from seedling. It's only about 2-3 tsp per gallon.

Hopefully when my ppm meter comes I can take care of this... But if anyone has any more insight, I'm all ears.

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My big bloom must have been different. Although it has been about 6 years since I used that stuff. Once you run out of fox farm hydro nutes I'd recommend just buying GH micro, bloom, and koolbloom or the botanicare lineup. Both of those treated my plants better and were more stable in the res.

Cool thanks, I'll have to try GH. (What does GH stand for?)

I'm thinking more and more this is a mg deficiency... Grow Big has .60% mg but is that enough?

I want to flush the container and add some epsom salt only, for a few days... Advisable? Bad idea?? What do you think?

I would not advise giving nothing but epsom salt solution to your plants. Typically tap water contains enough Mg for plant needs, however MJ being a Mg hog I would advise getting Botanicare's CalMag.

GH = General Hydroponics.

GH stands for General Hydro . I had the same issue with Mazar I gave it a cal/mag supplement the spots went away

Got my ppm meter. Water was around 445 ppm which sounds like it's on the low side no matter how I look at it. Still, my plant is showing symptoms like it's nute burn....! The new growth's leaves are VERY curly (like a claw) and the growth just a bit older already has rust spots and yellowing...

I added .5 tsp/gallon of epsom salt last night since I read it's safer than CalMag... And a few more drops of Super Thrive... Argh.

I'm waiting for my water pump to arrive in the mail to change my water... But if she looks worse tomorrow I guess I'll have to change the water the old fashioned way...

Okay. Got a nasty shock of algae growing in the tub. (I think it was due to some twine I had in the tub with it; it grew some nasty brown crap all around it and got on the roots.)

What I did:
- Washed down tub with antibacterial soap
- Let a diluted mixture of water and 10ml/gallon of hydrogen peroxide sit in there for 30 min
- Rinsed a buncha times
- Put plant back in with ph down, 5ml hydro peroxide and 1 drop/gallon of SuperThrive...
- Will wait 2-3 days before nuting again and will nute VERY slowly, incrementally

Thanks for everyone's help...

I hate to say it maitai...it's the beginning of the end. 85 is way too hot for the res. I've been there...I went back to soil. Soil WILL tolerate high temps...100+.

Good luck...my roots eventually turned black. I pulled them from the DWC and stuck them in a 5gal bucket full of soil...they were fine.

Fuuuuuuuuuuuuuuuuuck. Is that why I STILL have algae, even though I thoroughly cleaned it out just a day ago? I spent so much money on hydro stuff... Sigh...

Right now my roots are covered in brown crap. Algae covering the sides of the tub again... Is there any inexpensive way to lower the temps in the res??

Go ask the hydro guys...maybe they have a cure for you.

I hear you, I sprung for all kinds of pumps, airstones, and net pots. It was AFTER I had started a grow that I learned how critical low temps are to a recirculating res...like my DWC. My temps were in the 90s and all hell was breaking loose.

They grew like mutherfuckers until it started getting hot during the day. I battled with h2o2 and draining and cleaning, nothing kept it at bay. Then one morning...I found roots that were 1/3 black. I threw them in pots of soil and they grew just fine.

You always have that as a backup...hint hint...go buy some...

Good luck!

After picking up the idea on some other forum, I'm gonna go buy a mini fridge and stick the cooling thingamajig into my res... Says it worked for the guy, 10-20 degrees cooler. Will report back with my progress, wish me luck.

best of luck to ya..

maitai said:

After picking up the idea on some other forum, I'm gonna go buy a mini fridge and stick the cooling thingamajig into my res... Says it worked for the guy, 10-20 degrees cooler. Will report back with my progress, wish me luck.

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Great idea...but it seems like a lot of work buying a fridge and taking it apart to cool your res.

Good luck!

Well it sure beats buying a $300+ cooling system... The fridge was $40. Hacked some of it apart yesterday and will continue doing so today. (Perhaps a tutorial can come out of this madness...)

For now I am trying to keep it cool by adding 1 liter frozen bottles to the tub 2-3x a day, though I'm sure I don't do it enough (8-9 gallon res water).

I wish you the best...mine ended tragically as far as hydro goes...but the plants were fine.

You just can't beat a DWC for fucking fast growth...it was unbelievable while it lasted.

Like I said, I had no time with those black roots.

Good luck with your project, I hope it works out well for you.

You know, running that compressor is going to make some heat. Along with the heat the refrigeration process produces. You have that worked out? Remember, if it's taking heat from the water...and water holds a LOT of heat...it has to put that heat somewhere.

I'd like to see the finished product.