Tadpoles in Tanks
Introduction to the Project

TadpoleTadpoles in Tanks forms the third step in our Creatures in the Classroom project. Tadpoles are found in ponds within the river catchment area of the River Wandle. The tadpoles born in and around the Wandle are young toads (Bufo bufo), frogs (Rana temporaria) or smooth newts (Lissotriton vulgaris) – they will all have been caught from our local area and will be returned to the same site after around 10 weeks.

As tadpoles these animals live an aquatic life beneath the water. However after some weeks they will metamorphosis in to miniature ‘adults’ with legs – at this time they move on to land. It is at this time that they will be returned to their natural habitat.

Resources supplied by the Wandle Trust

The Trust will supply:

  • A simple teacher’s handbook detailing the tank set up and ideas on how the tadpoles might be incorporated in to the Lower Key Stage 2 curriculum
  • Fish tank
  • Air pump, plastic tubing and air stone – tadpoles enjoy some oxygen going through the water
  • A floating boom on the top of the water surface where young adults can climb to safety – this piece of floating wood (acting like a lily pad!) can be put in to the tank as the tadpoles approach adulthood
  • Water collected from the River Wandle – the tank will be half filled
  • Gravel and stones collected from the River Wandle
  • Water plants collected from the River Wandle
  • Tadpoles collected from local ponds – you can expect to receive around ten tadpoles
  • A small net
  • On-going help and advice


The Tadpoles in Tanks project will be set up in early Spring as the spawn (eggs) hatch out. It is suggested that the tank be set up about a week before the tadpoles are introduced. This will allow time for the tank set up to be checked, the river water to ‘settle’ and micro-organisms (too small to see!) to start to work in the tank.

The Trust also offers:

  • FREE introductory presentation to classes – with images, music and video

All tadpoles will be released back to the habitat at the site that they were originally collected. The Trust would be happy to help organise this event (advise on a suitable site which is safe and accessible to children) but will not be responsible for transporting children to and from the release site.

Resources NOT supplied by the Wandle Trust

  • A second fish tank (with a secure hood) where the young adult amphibians will enjoy a place to walk around and hide – advice will be given on how and when to set this up.
  • A source of electricity and an adequate extension cable from the wall socket. Four plug extension required.
  • A tank stand – a firm table, desk or bench will be required to hold a weight of water!
  • A hose and bucket to siphon the dirt out from the bottom of the tadpole tank (see below) on a weekly basis.
  • Food for the tadpoles – boiled lettuce and dog food – but do not overfeed!
  • If you choose to ‘release’ the tadpoles (now miniature adults) back to the River Wandle transport to and from the release site will need to be organised for the children. Extra adult supervision may be required.

Expertise and Commitment

Tadpoles can be sensitive to their environment – overcrowding and overfeeding are the common problems in rearing them. Stress (through being handled by excited children) is another. On-going advice and help will be supplied throughout the project to make it a success. Newt The tank will need some maintenance including cleaning of the gravel (using a hose as a siphon and a bucket) and changing of the water (about a quarter of a tank) every week. The techniques will be explained in the teacher’s handbook.


The cost of the hire of the tank and accessories is UK £30.00. There is also a returnable deposit of UK £30.00 which will need to be paid upfront to ‘The Wandle Trust’ before the programme begins. This deposit will be returned to your school on completion of the project.

Frog More Information

If you have any further questions then do e-mail education@wandletrust.org If you would like your school to take part in the Tadpoles in Tanks project then email education@wandletrust.org. Please indicate in your email:

  1. The easiest way to get back in touch with you – telephone number (call or text?) or email?
  2. An indication of when you would like to set up the project – a month will be fine.

We will get back to you as soon as we can!

Quote: ‘I raise tadpoles every year in a tank. My pond is a very good newt pond and there were great diving beetles so they ate all the tadpoles (or most of them). This is what happens naturally of course but I never bred tadpoles as a child so I felt deprived. Once the tadpoles are free-swimming they graze on algae on leaves and the sides of the tank. After 2 or 3 weeks you have to start feeding them. I feed mine boiled lettuce. The lettuce is boiled to soften it for them and to remove any chemicals etc. Remove the uneaten mid-rib before adding another leaf. As they grow you can introduce flaked fish food once their back legs have developed. When front legs grow you must lower the water levels and give the little frogs somewhere to move onto out of the water. I put some stones in and cover with moss. At the moment I am releasing my froglets to the side of my pond where there is grass and plenty of cover from the sun and predators. Tadpoles in my tank develop a lot faster than the ones in my pond as it is warmer but they will develop at different rates. Bigger tadpoles release enzymes that stunt the growth of the smaller ones. Once the large tadpoles have grown into froglets the others quickly catch up. I also change the water regularly with fresh pond water left to reach the same temperature as in the tank. This will contain water fleas for the taddies to eat. I wish you lots of luck, hope this is helpful.’ (Teacher, 2013)

Useful background websites about tadpoles:

Young Person’s Trust for the Environment YPTE

Royal Society for the Protection of Birds (RSPB)

Amphibian Arc

Amphibian and Reptile Conservation