New to Hydro

21 years ago

Hello, newbie here.

I recently purchased a GH Aeroflow2. I started some tomato seeds in rockwool before I got the system, they are transplanted into the 3" cups with grow rocks, all looks great except the tomato leaves have started curling under very tight, their growth is amazing, no yellowing or spotting. All new growth looks normal for a few days they quickly curls under.

When I first got the system, I didnt have the Ph and TDS meters, but before my first water change (10 days) I got them and the ph was way high (7.5+) and the nutrients were low (500 ppm). The seedlings started exhibiting the curling about a week after transplant into the grow rocks. I thought maybe shock..., but 2+ weeks later, no change.

After the water change I got the ph to 6.0 (holding very steady, check twice a day) and the TDC to 1500 - 1550 ppm (fluctuates). I'm using the GH 3 part system for the nutrients.

I'm using a 400w metal halide approx 30" from the plant tops, the fan comes on with the light which is on 18 hours a day. I run the pump for the entire 18 hour light cycle, then for 15 minutes every hour during the night. The roots and leaves look great, except for the curl???

I thought maybe heat, so I raised the light a bit, no diff. Then I thought humidity, so I placed cups of water between the pots....waiting to see the results.

Please someone take a look at the pic and see what you think. Sorry for the horrible picture, its from my webcam, and obviously doesnt like hid lighting.

THank you very much, Talvi.

http://home.earthlink.net/~talvi/easywebcam.html

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Comments (6)

onewebfoot
21 years ago
Downward curling of leaves could mean overfertilization, infestations of whiteflies, or infestation of aphids. There could also be viral causes for downward leaf curling as well, but there would likely be additional symptoms if this were the case (yellow/mottled leaves or other symptoms). If there are no pests and no additional symptoms, then perhaps your nutrients are simply too strong (even though your range is well within that for tomatoes). I have read the hydroponic metrics for tomatoes is generally as follows:

pH= 5.5 - 6.0, or 6.0 - 6.5, depending on who you read, and I like the former range because Baci does too. :-)
cF = 20 - 50
PPM = 1400 - 3500
EC = 2.2 - 2.8

But because your plants are so young, perhaps you nutrients are simply too strong. Perhaps try diluting nutrients to half of current strength for a week.
Talvi
Original Author
21 years ago
Hello, thanks for your reply!

After a lot of reading, nutrients are what I thought too, but when the curl started, they seedlings were in the low ppm solution (500 as opposed to 1500 now)

The plants arent wilting, just curling, is it possible they didnt like the change from the flourescents to the MH?

I will try diluting the solution some and see what happens.

THanks again! Talvi.
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onewebfoot
21 years ago
Talvi, i guess we both had the same suspicion to start, but I don't know how to explain the lack of response from your plants given you had implemented reduction in nutrient strength before you posted. After a few more days, how are the young plants doing now? Have a great weekend.
hydro4me
21 years ago
Hi there Talvi,

I am also curious, since your pH and ppm's sound righ on the mark. If you are using a 400w MH, you might switch over to sodium for tomatoes. With 400w HID's you should be about 12" or closer for most light usage. Watch for buring or drying.

-Jason
Talvi
Original Author
21 years ago
Hi Onewebfoot and Hydro, I'm stumped.. Leaves are still very curled, but I'm getting a lot of blossoms! Some are actually pollinated, I'm happy, but still confused...

Hydro, I actually have a 400w Mh and a 75w HPS in the same setup with a light mover, I also have leafy veggies going too, so I want to keep the MH. Thanks for the tip on the 12", I did lower the light from 30 to about 24 after they grew some, I'm at 12" now, and watching close for burns!
NLG1
21 years ago
Are you adding the Flora Micro first to your stock solution. If not, this could be causing nutrient lock out. (percipitation) Also, the ratios that you use the three products together are really important. Are you on city water or well water? This curling could be a lack of calcium. Tomatoes are very calcium hungry.