I am just off a two week trip.  My son had a graduation on the East Coast, so I drove out for that and, since my parents are there, I spent a over a week with them.  Finally, I hit the (again excellent) AKA annual show in Illinois on my way back to Minnesota. 

Before I left, though, I had a big concern for several batches of small fry. 

I have left adult fish many times for a couple of weeks without any significant issues.  All reports are that asking any non-fishkeeper to feed your fish while away is a recipe for regret; overfeeding being the typical, but not only potential issue. Normally, if these were fry from my own pairs and more eggs could be expected when I returned, then I would not have worried about it, but I had a few fry from some imported eggs and I really didn't want to lose that species.

What I chose to do was put the fry (there were a dozen or less fry of each species) in plastic shoeboxes, added a lot of plants (java moss, Riccia) from a well established tank and also added water from my outdoor daphnia tub.  This culture was stared years ago using pond water so, besides daphnia, it contains cyclops, moina, volvox and goodness knows what else.  I put the shoeboxes on top of some larger tanks under a bright light on a timer in hopes of maintaining the algae there as food for the zooplankton and so the fry.

When I returned after 15 days I found that, not only had the fry survived, but had grown substantially. So this experiment was very successful.   Admittedly, though, had it not been the time of year where I had a ready and rich food culture to start with, I would not have been able to do this.  Perhaps that's a reason to keep an indoor culture going over each winter.  I have found in the past that this is not productive enough be worthwhile in feeding my fish, but it might be enough for a situation like this.