as long as the tap root doesnt sit constantly in ur water it should be ok , try it and if u see the seedling starting to show signs of over watering just revert back to what u where doing for another 2 days. also if u can try exhale co2 bags u should give them a go, i saw 1st hand lastnight the difference these can make in a small grow. these exhale bags had been added to the grow just on saturday and the grower told me that plants had grown 5/6" in 24 hours ( infact for the two hours i was there they had grew about another 1cm) the plants are 3 weeks into 12/12 and look super healthy but he maintained the bags have made them look better.