The Free On-line Aquaculture Dictionary

Photoperiod Control of the Smolting Process for S1/2
Stage Fish size Light regime Other factors
1 0.3 - 15g (75 - 80mm length) 24 hour light Fish must achieve this size by the end of June. This is usually achieved by using heated water for incubation and first feeding up to about 2-4g.
2 Fish held on 12 hour light / 12 hour dark for 10 weeks
3 24 hours daylight After about 6 weeks of 24 hour light the fish smoltify
Other methods include holding the fish on 24 hour light until midsummer and then on natural daylength until mid-October. The fish then progress on to stage 3 and smolting occurs 6-8 weeks ahead.