Made a 2.5L starter pitched into an IPA yesterday after aerating with pure O2 for 90. sec, I also used 1tsp of yeast nutrient 10 min left in boil. Fermenting in bucket, temp is 66-70deg and 24hrs later zero airlock activity. Popped the lid and there is krausen forming but no CO2 bubbling. Is this normal for 001, never used it before but seems slow seeig I aerated and used yeast nutrient plus a nice starter. Thanks for any info.