HELP! 1st time cloner

OK... I have 7 cuttings that were taken on March 14th (2 weeks ago) They went into RootRiot cubes with a squirt of Root!t gel then into a propagator in my growroom under 400w sodium 24/7. Humidity in the prop is 24C-28C. There has been new growth although no roots showing through cubes yet.
HERE'S THE PROBLEM... Yellowing tips and/or edges on the taller cuttings! I know this is a defficiency in either N, K or both but I would've thought the cubes would be OK for more than 2 weeks. I'm planning to pot-on into small pots using Plagron Royalty Mix which again is supposed to have all that they need for a few weeks so at the minute they have not recieved any additional nutes other than what's in the cubes and gel. Will moving them into the Plagron help with giving nutes? What else can I try?

They do sometimes get ugly before getting pretty. You can give them some 1/4 strength nutes if you like or wait for them to turn the corner.

Little Tommy said:

They do sometimes get ugly before getting pretty. You can give them some 1/4 strength nutes if you like or wait for them to turn the corner.

Click to expand...

LOL! Thanks man. I've put the more yellowing ones into the Plagron now to see if they can draw anything from that. Fingers crossed...

I usually see yellowing just before they start to root. The 400 HPS might be a bit too intense for them , i use a 26 watt CFL to root with.

i agree with little tommy mine sometimes look like shit and after awhile they turn the corner little clippin and tlc turn into great plants killer saying about bad day in the grow room

ink the world said:

I usually see yellowing just before they start to root. The 400 HPS might be a bit too intense for them , i use a 26 watt CFL to root with.

Click to expand...

I've got a shade from the back window of the car hanging between the light and the prop so they quite shaded and not under intense light.