??

[Rose]

Okay, so here's the setup:

Grow tent size - 50cm deep, 1m wide, 1.42m high
Mylar - reflective diamond shape
Light source - 240W LED panel (blue & red) with some LEDs remaining unlit
Exposure time to blue spectrum during veg - 18/6
Pot size - 8L air pot
Substrate - Plagron Royalty soil
Plant hydration medium - bottled water

Eight seedlings have bitten the dust so far and I know the error lies with the setup. I never had a problem with growing autos in the UK but since the move, every single one of the plants took the same turn. In the UK my tent used to be 1.80m high but I doubt that made the big difference. Indeed there are some LED bulbs that look blackened and do not light up anymore. The majority of the e.g. blue ones do work so I'm a little surprised to see effectively every plant wither right under my nose!

Any ideas on what might be going on?

The withering auto White Cheese:

 

[alley_walker]

Even though it is bottled water, You still have to PH it. You also might be dealing with a little LED bleaching. Hard to say! Nute burn perhaps.. That can't be ruled out either... Try backing off your LED a few inches, flsuh with Ph'd water with no nutes for 5 days or so.. There is a lot happening here. Hopefully you get a few heavy hitters in here that really know there stuff..!! I will be checking back in.. PLEASE keep us posted ok?

 

[GoAuto6]

I'v had bottled water that ph's at almost 8., I think you should test your ph..

Rough Calculation Guide:

Here's some good info on ph.....
If your runoff pH is higher than your starting pH, use this equation to determine your soil pH:*
Soil pH = Runoff pH + Difference

If your runoff pH is lower than your starting pH, us this equation:
Soil pH = Runoff pH - Difference.

For example, say your the starting pH of your solution before it goes in is 6.5 and the pH of your runoff is 7.0. The difference is +0.5, so using the above equation:
Soil pH = 7.0 + 0.5*
Soil pH = 7.5

If your starting pH is 6.5 and your runoff is 6.0, your difference is -0.5 and using the above equation:
Soil pH = 6.0 - 0.5
Soil pH = 5.5
​

 

[WVTurtle]

Last time I ph'd Nestles bottled water I think it showed 7.5-8. Those pics look like nute burn to me.

 

[The Squid]

Just checked out the ingredients for your mix and yes I believe it's a bit too hot for your seedlings. Are you Phing your feeds?

 

[Rose]

For 1-2 plants per grow in the tent I water them manually as & when they need watering. The pH from the Volvic water I used was 6.5 when it went in - I didn't measure the pH of the run-off water though, d'oh @ me! What I did do was to water the Plagron soil first until water came out of the bottom of the pot, let it drain a little and then planted the seed in its coco/peat plug into the pot of soil. It went off to a cracking start although the plant didn't manage to maintain the lush green color on the leaves.

I have been using the Plagron Royalty soil with success on the Ultra Violet, Smurfberry, Titan & Onyx. Since moving countries I have also used regular houseplant soil, BioBizz All-mix and the Plagron Royalty soil - all give me the same result: a stunted plant around the 2nd tier of leaves... I have used bottled (Volvic) water, regular tap water & boiled tap water - no difference as far as I can tell.

Thanks a lot for the rough guide on pH calculations, GoAuto6 I'm going to check the run-off water's pH after work today. It does break my heart to think that eight perfectly fine seeds went to waste!!