[starry]

Think thats what I mean  I am going away for a week on saturday and have left my very resonsible son in charge of the watering, however I am a little concerned about my seedlings an wondered if I can do a quick diy version to keep them moist 

[Optimistic Gardener]

Certainly can.  I find it very useful stuff.  I use it throughout the year in my greenhouse as I work f/t and can't always guarantee being able to water twice a day every day.  It's a bonus when I come to go away for a fortnight's holiday as well.  You can add a drop of feed to the water resevoir as well.  It'll be more than adequate for your seedlings for one week.