Help with seedlings

5 weeks old grown in coco. Under 600w hps, previously 125w cfl. Given a couple of quarter strength feeds of canna a + b. Anyone have any ideas why rate of growth is so slow and what I can do to help them?

Another pic

take them out the clear cups, lights are bad for roots, let them dry out before watering, these pics looks like they are wet, get them in a proper plant pot and let them dry out so the roots stretch for water.

iikode is right, get them in larger opaque pots. if not then tape a few layers of paper around the cups. they are very small for 5 weeks, they will want larger pots.
whats your ph?

I would change pot and get you some roots organic 707. They'll voice back like shit.

Man,they are well small for five weeks.I've got some five week old AK47's under 600 watts MH bulb for veg only already transplanted into 11 litre pots and they're a foot tall with nine nodes.Gotta agree with Iikode,too wet and looks like they're stretching for light.How far are your lights away? Get yourself a moisture probe meter off of ebay for £5,lets you know exactly when they need watering.Right now I'd take them out of those cups,put them in six inch pots and give them 100ml water per day to start and try to cover the whole top of the soil so that the roots stretch to get a drink.
Good luck man

Thanks for the suggestions. Put them in more appropriate pots now. I've got some clonex mist, will that help with root development? pH is 5.8 btw.

I see several issues M8.

1. the soil needs some perlite and/or vermiculite - aids in moisture control and keeps them from drowning which it looks like they could in that soil mix
2. keep that light a good distance from those seedlings - they are delicate at this time and only need a fraction of a 600 watt light
3. get them transplanted into a container that is light proof to protect the roots and a little bigger than a solo cup
4. only water them when they are about as dry as a popcorn fart when they are that small and no nutes untill you get at least 4 nodes of growth.

Hope this helps

Peace and Great Grows

Asmallvoice