Growing dripper full auto hydroponic veg.

I have two confirmed pre-flowered true blue mums (Serious AKs) and have taken 2 clones from each which are in the propagation tray atm and looking healthy . The original plan was to keep the mums, grow up the young ladies and pop them over to the other room when ready, rinse and repeat on a 2 month cycle

Because of this the mums are in 12" pots (Root Riot + 4" Grodans and the pot filled will Hydroton pellets), pots are about 8" high.

However, the mums are already some 12" high under the 250w CFL (about 6 weeks from seed) and seem to be growing about 1" every 2 days. If they keep this up my CFL wil top out very soon The mums are already showing their fannies big time with lots of pistils on all the top nodes. On 18/6 every day. Canna hydro nutes 0.6 e.c. and around 5.7 pH daily adjusted.

So I was thinking maybe I'll take the mums over to next door, but over there its a Flood and Drain which is only about 4" high.

So should I carry on and use daughters, top mammies or take mammies over?

If i go with mammies, what is the best way to get them out of their 8" deep pots into a 4" deep F&D without traumatising the root system?

Thanks for any advice.

The nub.