reco,getting hps when it comes to the flowering phase, get a table over them now .
If pot size is a problem them i would get some cat litter trays with cori board cut out so the pot slides in,just makes ure you can get a compressor in there to the bottoms in the trays via air rings,or even air stones.this will mean the roots will continue to grow big but still been in the small pots.great way of growing its a little like auto pot growing but hand feeding unless you add ball cots to the trays it easy done.or just try and get some auto pots and then you can just keep your eye on the plants,i still check them but only if the two have not drunk 15 litre of water/nutes over night i know there is a blockage some where
tyke