watering new seedlings.

ok guys just wondering what would be better for my new sprouts. they are in a powergrower (the same as a waterfarm). and i am currently just using r/o water in the res. im just wondering is the r/o water not ideal at this stage because all the trace elements have been taken out. should i be using tap water instead? or should i be adding something to the r/o water?

Bump. Come on guys any help will be much appreciated

No nutes for the first week in seedling stage. Just r/o.. assuming its ph is sufficient.

Thanks void your a champ.