Got em under 4 25w t5s grow lights actually- yeah, not sure what was going on... i increased nutes slowly, they have picked up in the last week after topping them. They need a transplant about now for sure... i had the lights at about 8 to 10 inches at germ, then moved them down to about 5 inches after they got going- seemed pretty stretchy. Gonna throw under the 315w tomorrow morning
I think the number of nodes and smaller stems is what is kinda slow, not necessarily the height. If you're rollin 100w of t5 you should be doing a bit better.
Is there plenty of fresh air getting to that space? Is there a good amount of air movement? Both of those factors can slow growth considerably. The goal with this is to get the fastest root growth possible, and keep the momentum going. Basically your plants aren't getting the moisture sucked out of their leaves, making them use the water in the medium. Slower root growth will always yield slower top growth. Research plant vpd for a more in depth understanding.
Could be something even simpler. Someone else just said he was having issues with slower veg under t5. Turned out he had bulbs that were just past their prime. Unless you're using led, the bulbs need changed every 6 months to keep everything tip top. When you change your bulbs for your mh/hps you should do your veg too. I've had less dense harvests with hps bulbs on my 3rd cycles repeatedly until I made it a proactive measure, not a reactive one. I usually run 11-12 week plants so I use every bit of the best light the bulb has.
Maybe watering too much, letting the cups get pretty light before watering?
Hope that helps your issue.
Tomahawk #5 
