Hatching frog spawn at school

Hi folks,
This is a long one so please bear with me
I've talked myself into helping my son's class hatch some frog spawn.
The school's lucky to have a spinney with a pond, I went there today and - yippee! - got lots of spawn. So far so good
I'm a total novice in this whole amphibian business so need some advice please!
I do know they need regular top ups of pond/rain water, some plant-based food once they hatch and something meat-based as soon as they grow legs.
Now's to the questions:
- Container: At mo, the spawn's in a see-through plastic tub with air holes in the lid. When tadpoles hatch, I was planning to move them somewhere larger. What sort of depth is best? What about a recycling bin lid (5 cm deep)? Or can I use something like a toy storage box as long as I put some stones/bricks at one end?
- Plants: do I need an oxygenator, or should I let algae grow so tadpoles could eat them? Which is best, an oxygenator or a floating/cover plant, or do I need both? Also, native aquatic plants seem to be out of stock everywhere till late March. Is it really bad to take a plant from the pond if I can't buy one by the time the tadpoles hatch?
- Site: I'm assuming the spawn tub would be better off in the shade so it doesn't overheat? What about the tadpole container? Sun or shade? The playground doesn't have any dappled shade.

TIA for any comment!

PS Do I fuss to much?

 

I wouldn't try to hatch/rear too many tadpoles in a small container. They'll be fine at first, but as they grow you'll have problems with the water quality. A whole clump of spawn will be far too much - best to just keep a small part of it and return any surplus.

Important not to let it overheat, as you say. Development/growth will be faster in warmer temperatures, but full sun could overheat the tank very quickly. Is inside the classroom out of the question (away from the window/sun/radiators)?

Plants - you don't really need any. Oxygen comes from the air by diffusion, so so long as there is a decent surface area in relation to the number of tadpoles they should be fine.

Food - I've fed them in the past on boiled nettle leaves/tops. Smells quite a bit though in the kitchen, and perhaps not suitable for school. Raw lettuce/spinach should be fine.

A small hand net is useful if you have to change the water or move them, and to remove waste/uneaten food. The kind you can get at aquarium shops.

I don't think container depth is that important, but I wouldn't clutter it with bricks etc. initially. More hassle when cleaning out. Save that for when they get older. When the tadpoles get to near froglet stage, they become very vulnerable to drowning. This can happen earlier then you expect, so they need to be able to get out or at least have something to rest on at the edge/surface. Or you can release them back to the pond at this stage.

 

Whats a spinney ???

 

KingEd - you are my hero! I posted this on several forums and you're the only person who's replied!
Yes I know a larger container is important, I'm just not sure what kind. And school being school, they'd want me to pick one and stick to it! I fear too shallow could overheat, and too deep and the spawn would sink to the bottom where presumably it could die? (read that somewhere) At mo the choices I have are, a plastic tray which could hold about 5 cm of water (up to 10 L?) or an old recycling bin which could hold 3-4 buckets but that's too deep if there's no support/shallow end. A plastic sandpit would be ideal, suppose I could ask freegle?

Indoors - yes they actually had them indoors today but I was worried they'd get too hot, with the heating still on! I moved the tub out into the veranda for the weekend but not sure where it'll end up come Monday.

The food I'm not so fussed about, I've read tadpoles eat chopped cucumbers and lettuce so that's the easy bit. So long as the kids don't overfeed them!

I know they don't need plants but I thought it would be good for the kids to see them in a more natural environment. Besides, plants would provide support and possibly even food for the tadpoles. So I'm still looking.

The frogs are going back to the pond eventually but I bet the kids would want to see them hop about for a bit before they are released.

 

just a posh word for a thicket of trees basically what's left of the vast sprawling forests of deep Hertfordshire!

 

I don't think the container will overheat unless it's actually in the sun, but 5 cm deep doesn't leave much margin for error. A sandpit shape would probably be good. Naturally tadpoles do congregate round the edges where it's warmer, which speeds their development.

The froglet stage is the most difficult to cater for because the conditions needed are so different. As well as drowning they're at risk of desiccation in a dry/bare environment. Apart from an easy transition between water/land, they really want somewhere where they can hide and look for food such as springtails, tiny insects and spiders. E.g. leaf litter, moss, long grass, pieces of wood/bark.

 

yeah I did just think of wood! I've got some pieces of old tree roots lying about the garden. It was a cotoneaster tree that suddenly dried up and died last winter. You don't suppose there could be any fungi or viruses that affect both trees and amphibians? sounds far-fetched but who knows I wonder if I could somehow balance the spawn between two floating bits of wood so it doesn't sink? Would be good for the kids too, they'd be singing the 5 little speckled frogs on a log song all day

Forgot to mention, the pond was completely covered in duckweed and some got in the water I took. Is duckweed good for the tadpoles do you know? Would they eat it maybe? If so, how could I encourage it to multiply?

If I could just get an old wheelbarrow from somewhere... that would work even better than a sandpit!