HELP: Plants growing far too slow!

Hey guys, this is my first grow and I am running into some problems. I noticed upon comparing ops of a similar age, that my plants are grossly undersized. I also notice they seem to go through periods of really slow growth, then really rapid growth.

E.g, when I transplanted them to the hydro tank and added nutes (transplanted from just rockwool), i noticed major growth, that has since slowed down.

I planted these guys on May 9th, it's been 3 weeks and 4 days, and here is a picture of them taken today. My best plant is also pictured.

The plants seem relatively healthy.

I am wondering if my light is too close to the plants. From the plants right under the bulb, there is 8-9 inches to the bulb, but the temperature is totally fine and there are no signs of burning.

Also, my humidity shoots up at night to like 85% and drops to like 20% in the daytime, another issue?

I have been experimenting with 3 different watering levels right now (high, drip, and none) and am going to see what plants perform the best over the next 3 days to determine if I am over/underwatering them.

Also, I added enough nutrients for a full plant, yet they are borderline seedlings, could this be responsible for the slow growth?

Any ideas??

my *guess* is inadequate ventilation.

back off the nutes ...only give nutes after the 2nd or 3rd week at 1/2 strength...ur plants r stretching get the lights closer...a couple are also a little droopy..signs of ovrwatering

I noticed the overwatering thing, thanks.

It's well ventilated with a 392 cfm 6" fan, so I think that should suffice.

The stretching all occured with the CFL that I started with (a 32w CFL) and since the nodes have been super close.

I'm going to add a few litres of water to dilute the nutrients, thanks.

Can putting the lights too close cause the plant to not grow fast enough?

It will make the plant stay shorter and bushier.

i would like to offer a tip, that res is all black, and your res area wont get much algae, but the temp in that res is going to be scorching under lights. a little reflective tape, or maybe a white vinyl covering is really going to come in handy.... imo

Steveat1 said:

i would like to offer a tip, that res is all black, and your res area wont get much algae, but the temp in that res is going to be scorching under lights. a little reflective tape, or maybe a white vinyl covering is really going to come in handy.... imo

Click to expand...

so you're saying the water temp might be too high?