Slow growth

[qs2087]

I have a 2 week old plant which grows very slow, would like to hear your opinions what can be a reason.

Temp: 26-29
Humidity: 50-75 (around 70 during last 3 days)
pH: the water is around 6, the ground meter shows more than 7, not sure how accurate this probe is.
Watering: every 3 days.
Nutes: RootJuice from BioBizz 5ml per liter
Light: 1 8W LED and another one 6W LED

Please help

 

[c526]

what is that soil?? after your next feed, capture the runoff and see what that ph reads,(runoff will tell you the soil ph,Ideally what goes in,is what you would like coming out)

Im not sure about the led,ive never used those,I use the cfl (23wt)and get them closer.

 

[qs2087]

the soil is coco-perlite 50-50
the runoff is muddy so its hard to tell the color but it looks between 6-7

 

[c526]

coco runs in the middle of hydro and soil as far as ph goes.between 6-7 is a huge spread.I cant speak for all,but i track my ph down to the thousands

if you're going to want to be a success ,I really advice a good ph pen,then there is no guessing.

What brand of coco?they are not all created equal. perilte,is it box store brand or nursery??

 

[qs2087]

could you advise what counts for a good pH meter?
the soil is a ready mixture (50kg bag), not sure how to tell which coco it is
ive already grown pretty much successfully in this soil but i dont know what i am doing diffidently now
maybe the temp only (the more successfull grow was in the winter) but as far as i read this is within normal range

 

[c526]

a good ph meter is 200,a decent ph meter is 75 the disposable ones in the 20 50 range will work,but the accuracy sometimes is crappy
I use a nutra-dip meter,I consider it the best tool,most used peice of equipment I have

If you need to get a cheap one,make sure you get the calibration solutions,then after you calibrate it,,,
grab FRESH GALLON OF WATER,PH it---write it down---add first nutrient---write it down-next nutrient---write it down--see where im going?? then if you ever have an issue,all you need to do is look back at you're records,and have a rough idea how you did it before.
I only use test strips in the outside gardens,indoors is way to important to me

the reason I asked the brand,is its not all created equal,some needs pre washing,some needs rinsed in cal mag,

 

[Antics]

My first guess is that it's your lighting.
Not all LED lights can grow Cannabis. The wattages you listed seem on the low side as well. 6 watts and 8 watts. I would suggest finishing the grow with CFL bulbs (at least 4 for Veg, and 6 for flower, per plant) Or consider upgrading your LED lights to a new model from our sponsors: Sponsors : 420 MAGAZINE ®
Further, LEDs aren't the best for young seedlings. You'll also have better luck using CFLs for the young seedling stage.

I recently just bought a light from one of our sponsors, TopLED and love it. You can search around the forum in grow journals, and find growers just like you using all different LED lights from our sponsors that are proven to work.

 

[labexperiment]

I agree with Antics, it is the light no doubt about it.

 

[theengineer]

without doubt, the light; as well as not being powerful enough, they're far too far away - get CFLs, 25w from Amazon and get them an inch above the plant - in two weeks you'll have a 6 inch plant ready to flower

 

[Fuzzy Duck]

Ye mainly poor lighting as many have said above


Mmm being an ex biobizz nutrient man myself & i know some of their nutrients are said to work with coco coir but honestly their not that great with coco coir... & yes i did try but only once, that being enough to explain what i thought about it !


How ever Biobizz with soil is great & had many successful grows


Other wise if you wish to continue with the use of coco coir you may want to look around for coir label nutrients, yup they do exist & HESI is a good brand which springs to mind, been using them myself...

If not coco coir label aka hydro nutrients you may want to bolster with a Ca, Mg nutrient supplement as coir has a little habit of stripping these nutrients or making them hard to get by the plant.

 

[qs2087]

Thanks guys, looks like there is a consensus here about the lightning so I replaced the LEDs with 30W CFL and located it 15cm from the plant.
About the distance - since I want high humidity I turned off the fan (venta) but the temperature is already 30C so I am not sure that I can place the light closer to the plant. I actually have 3 choices about it, what do you think is best here:
1. Turn on the fan (humidity will drop to ~50% from ~75%) and put the light closer.
2. Put the light closer and risk a burn of the plant.
3. Leave the situation as is.

 

[Tead]

so I replaced the LEDs with 30W CFL

Why not use both?

 

[Antics]

Thanks guys, looks like there is a consensus here about the lightning so I replaced the LEDs with 30W CFL and located it 15cm from the plant.
About the distance - since I want high humidity I turned off the fan (venta) but the temperature is already 30C so I am not sure that I can place the light closer to the plant. I actually have 3 choices about it, what do you think is best here:
1. Turn on the fan (humidity will drop to ~50% from ~75%) and put the light closer.
2. Put the light closer and risk a burn of the plant.
3. Leave the situation as is.

Are you using an exhaust fan?
The light can be as close as 2.5cm without burning the plant. I put my lights between 5cm-7.5cm and have no problems.

 

[qs2087]

yes its an exhaust fan, the place is really small 30x60x40 cm

 

[Antics]

I would say turn the fan on to control temperature. All of my plants so far were more sensitive to temperatures too hot, than humidity too low.

 

[v3gas4ce]

Agree with Antics.
Temp > humidity.

If you have a closed environment, you can easily adjust low humidity by foliar spraying, but 50% RH does t seem too bad.

 

[qs2087]

Getting the 30W CFL close didn't help much so I switched to 80W CFL and put it 5cm from the plant, but I didn't see any significant improvement. I week later it looks almost the same (3 weeks from seed) and in addition the plants looks like its turning yellow, especially the lower leaves. Thought it is is pH related but I measured the waste water and it was 6.8, so I don't think its it but I lowered it anyway to 6.6.
Here how it looks now:

 

[Tead]

hmmm... I must ask....
I notice you said you were using an 80w cfl. I don't usually see that wattage. The max wattage I normally see in standard CFLs is ~25w.
Are you using the "equivalent wattage" number or the "actual wattage consumed" numbers?

 

[qs2087]

I thought someone might ask but its not a mistake, I mean the actual wattage, its a one big CFL

 

[Tead]

Had to ask. Thanks!