These bottles are much bigger than PET bottles for drinks. You can easily get such bottles from the building maintenance department of your building. Used for storing detergent, you have to make sure you wash them well. The better option is to get from your hawker centre where these bottles are containers for soy, chilli or tomato sauce. Food grade and easier to wash. Besides that, the hawker will be more than pleased to give to you
Building the SIP from this 5 Litre bottle is similar to that of other PET Bottles. Cut the bottle 100mm from the base. Put holes on the top half – these holes allow water to flow in and roots to get to the water. Invert the top and push it into the bottom half.
Finally, wrap with aluminium foil. Add LECA to about 50mm and then potting mix.