Help with my young seedlings.

Hello... "a hydroponic grow"

I have four seedlings all 5 to 8 days old and each one is a little bit more advanced than the other... my most mature of these is 60 mm tall with two 10 mm leaves growing from the post germination cotyledon leaves...

To get to this stage i planted my germinated seeds in rockwool which i correctly prepared ie. ph 5.5 , and then kept them on my window "indoors" during the day and under a 20 watt warm colour cfl at night... i also watered each plant with 50 ml of water twice in this period ie. last tuesday and friday evening, and observed continous growth.

Today i moved my four seedlings into my grow room under a 250 watt metal halide light with the intention of operating an 18/6 photoperiod at a distance of 0.75m . The air temperature averages at 27 degrees at plant level and humidity is not an issue.

I think i might water again tomorrow evening and have been informed by two other Rollitup users not to begin nutrient feeding until the third or fourth node... "is this sound advice?" does anyone with a similar set up or who has experience with hydroponics agree with this advice????

Please help as these are my last four seeds and i need this to be a successful grow.

Thanks

Yes it is

Don't feed nutes for at least 2 or 3 weeks....your plant needs some decent time to develop itself and start a nice set of roots. Giving it nutes would be like giving steriods to a newborn baby....

Let the plant establish itself, then start working the extras in

your advice is much appreciated..