My auto grows really slowly

This is my first attempt as a grower with a hybrid auto.

I understand my setup is not ideal, but I had practically zero budget and I never expected any serious yield, it was more of a proof of concept effort so I could then decide what to invest in.

On topic, seed was germinated in paper, then put in a 7.5L container with an assumingly quality organic soil, plus 1/5 perlite I mixed in.
Above it looms a single 25W natural light led lamp (equivalent should be around 200W) around 30 cm above the plant. There is also a small fan at an angle to create a breeze that gently moves the plant around. I keep the lamp on for around 20 hours a day.

I live in a mediterranean country so humidity/temperature inside is fairly average/mild so I water every other way. (My City's water ph should be around 7.2-7.5 depending on stuff.

The thing is, the poor plant has been there for a bit more than a month and it's still around 5.5 inches tall. It seems to be growing but at a very slow pace which is quite problematic considering it's an auto. I have also noticed some of the leaves to develop a brighter shade of green on some parts as seen in the pic.

What could cause this? I have yet to notice any bugs, nets, dust and generally pest related stuff...

Looks like there may have been something on her, there are holes in that back leaf. Take a peak at these charts, it may help you some.

Your tap water should have chlorine and stuff out of the tap, let it sit some time and make sure your water never gets above 23C. Can even aerate the water before watering.
That pot doesn't breathe very well, you have to let oxygen and carbon get into the soil; whatever budget should have some beneficial bacteria for optimal performance of any nutrient.
Your LED is probably getting your leaves heated up to 40 celsius so you need to get the ventilation to make any use of light.

If that is a Diesel auto, rev the nuts off it

Tha

PissingNutes said:

Your tap water should have chlorine and stuff out of the tap, let it sit some time and make sure your water never gets above 23C. Can even aerate the water before watering.
That pot doesn't breathe very well, you have to let oxygen and carbon get into the soil; whatever budget should have some beneficial bacteria for optimal performance of any nutrient.
Your LED is probably getting your leaves heated up to 40 celsius so you need to get the ventilation to make any use of light.

Click to expand...

Thanks for the tips!
So how to improve the breaching part? More perlite and raking?

Felt pots