Seedlings bending at the base

[zieglerj]

I'm growing six seedlings in a hand-watered hydroponic system. All the seeds sprouted at various different times. My oldest, when it hit 2 weeks, just flopped over at the base. I had read that this happens sometimes so I just wrote it off to it growing too top heavy for the stem to support and propped it up on a home-made stilt to hold it up strait. But now, almost a week later not only is the oldest still weak-in-the-stem but then next oldest started doing the same thing!

Right now I've got both of them propped up but I was wondering if that's the right thing to do and what might be causing this pattern.

Not sure if any of this is pertinent but here's more info on what I'm using:

Started in rapid rooter then put in gro\dan delta rockwhool.
Using Pure Grow Plus nutes
Using tap water ph 5-6. (I'm using one of those liquid dropper test kits so I can't get an exact read).
Germinating under florescent lights.

 

[burris]

It sounds like your light is to far away from the plants... which is causing them to stretch....try placing the lamp closer but not burining the plant

 

[itsgrowinglikeaweed]

It's a combination of distance from the light and also you need wind (a slight breeze)to give the stem some "exercise".

 

[jaybee007]

lol i had exactly the same thing with my lemon seedlings they r just top heavy mate mine about 4 weeks old now and r about 9 or 10 inches and theyve only just started standing up straight without any help give them a few weeks ant they will soon stiffen up

 

[zieglerj]

The light could definitely be it. Even the ones that are still standing straight show some signs of light stretching. I'll get some more chain and lower it.

Should I give them a breeze while the oldest two are still like this or would that hurt they're recovery?

Thanks guys!

 

[burris]

yes give them a breeze it will help them strengthen their stalks. kinda like physical therapy

 

[zieglerj]

Ok, I made the changes. Put the fan up so it's blowing on the plants (on low) and dropped the light to about 3 in. from the top of the oldest. Since they're florescent, the bulbs stay pretty cool. I'm not too worried about burning.

Just another reason to convince the wife to let me buy a hps.

 

[burris]

Ok, I made the changes. Put the fan up so it's blowing on the plants (on low) and dropped the light to about 3 in. from the top of the oldest. Since they're florescent, the bulbs stay pretty cool. I'm not too worried about burning.

Just another reason to convince the wife to let me buy a hps.

haha good idea.. just put your hand between the top of the plants and ur lights. and if it hurts ur hand it will hurt ur plants.

 

[itsgrowinglikeaweed]

You dont want to veg with a HPS trust me. CFL's are much better for vegging. 3 inches is about right. I flower with a 400w HPS + CFL's and trust when i tell you the plants like flouro light MUCH better.
[" Plants use mostly red and blue light. Yellow and green light is of little use to them, so light that is emitted in these spectrums is wasted energy. Most of the light emitted by HPS lamps is in the yellow spectrum. Only a small amount of the emitted light is is in the orange or red spectrums, which plants use efficiently. Warm white fluorescents (2700 Kelvin) emit a greater portion in the red and orange sectors.
Although fluorescents produce only about 75% of the light per watt that the HPS does, the amount of light usable by the plant is equal or probably higher with the fluorescents.]" -Ed. R.

 

[zieglerj]

Yep, I'd heard that before. With these bulbs I can actually hold the bulb in my hand and it only feels warm. I've got three of them on the plants plus a cfl up a little higher and off to the side. Still I've been trying to convince my wife that we should really splurge and buy a ballast and hps bulb before they get too far into veg.

 

[zieglerj]

That's interesting. I hadn't heard that before.

right now the bulbs I'm using are three tube style blueish bulbs and one 120 watt cfl that looks more orange. Kind-of accidentally got the right spectrum.

You dont want to veg with a HPS trust me. CFL's are much better for vegging. 3 inches is about right. I flower with a 400w HPS + CFL's and trust when i tell you the plants like flouro light MUCH better.
[" Plants use mostly red and blue light. Yellow and green light is of little use to them, so light that is emitted in these spectrums is wasted energy. Most of the light emitted by HPS lamps is in the yellow spectrum. Only a small amount of the emitted light is is in the orange or red spectrums, which plants use efficiently. Warm white fluorescents (2700 Kelvin) emit a greater portion in the red and orange sectors.
Although fluorescents produce only about 75% of the light per watt that the HPS does, the amount of light usable by the plant is equal or probably higher with the fluorescents.]" -Ed. R.

 

[itsgrowinglikeaweed]

CFL's get a bad rap. They make awesome buds. They're just not good for BIG plants.
Fluoro tubes are a little different, but still work great for seedlings. They should be kept under an inch away.