Question: 

 

Why does 32mm pipe from my local DIY store in the UK not fit the ClariSea?

 

Answer: 
 
Aquarium plumbing and home plumbing, very confusingly, are 100% NOT compatible.
 
For aquarium use, you want to use 32mm pressure pipe (grey colour). 32mm pipe from DIY stores, plumbers merchants, etc (usually white or black) whether push fit or solvent weld will NOT be the correct diameter.
 
The correct type of pipe can be purchased from any good aquarium shops. The chart below shows the actual sizes of 32mm pipework designed for different applications.
 
The specification highlighted within the green circle is the compatable size pipework for the ClariSea, the specification in the red circle is not compatable.