Cold temps, not enough light, too much water, too little water, no air flow (dank-musty-moldy), are all causes of slow growth. Pick the most likely and start there, that is if you have ruled out a nutrient problem. If you want to be sure on the nutrients, flush it as many times as you can stand with PH adjusted water and let it nearly dry out, then start adding a tiny bit of superthrive to the water. Your picture looks like you may be using soil which in my book is a big no-no, but the concept would be the same for hydro. If you want, hydro can be literally as easy as dirt, with 50 to 100 percent additional yield. Why not go hydro, please call today, operators are standing by.

I can't really see anything for scale, but it does look much smaller than mine would be at 9 days. But I go hydro and HID lights, which makes a huge difference. It's the only real way in my opinion, unless you use a shitload of expensive flouros. As far as I know, it looks just slightly smaller than it should for growing in dirt. If you just have a couple of weak flouros on it, you can pretty much expect it to have a growth rate next to hybernation, especially if they are far away. They should be nearly touching and can be touching if they have a plastic shield over the bulb.