Website's of Parts

 
 
The Solarbag 1-2-3 and the blue hose I bought at FUN.   https://www.fun.be/solar-bag-1-2-3.html or use 50 meter Black Garden tube 25mm.
 
The pump (SP20/20 Easy Connect Water Circulation Pump  12 Volt 14 Watt) and connectors, I bought at http://www.solarproject.co.uk/  
 
 
and The Adaptor/Reducer hose
Hozelock hose/tube reducer 25mm - 12mm, hose/tube reducer 32mm - 25mm, 
and a piece of hose/tube 10 cm X 25 mm.

or make it yourself: With different hoses of different diameter, about 15 cm long.