Sand filter

Pros : Usually cheaper. Can contain activated carbon to remove some of the chlorine, if you want to. Some companies allow you to customise the content. They may have the option of adding zeolite that helps soften water, which in turn increases the efficiency of your washing detergent. Usually you would need to replace media in about 5 years. Periodic backflush helps prolong lifespan. Relatively cheap to replace the media.

Cons : Water is not as clean as membrane, can only filter up to maybe 20 microns. Larger vessel, takes up more space. Typical design of sand filters has a plastic mesh at the bottom of the intake tube that prevents sand media from flowing into water supply. If that plastic mesh breaks over time, sand will contaminate your internal water supply, possibly damaging your appliances etc. Some sand filter vessels are of poor quality, allowing sun light to penetrate. This would make the sand filter a breeding ground for algae, etc. Check the vessel, make sure light cannot penetrate( you can use a torch light and shine from the outside while you look inside).


Membrane filter

Pros : Much cleaner, filters up to around 0.02 microns. Usually takes up less space. Usually has automatic flush ( but it is not a full backwash ). Almost all vessel is made of stainless steel, light cannot penetrate making it less likely for algae growth.

Cons : Generally more expensive. Automatic flush is not a full backwash. You will need to engage the water filter company to do a powered backwash every 1-2 years to clean the dirt accumulated in the membrane (You will be amazed at the amount of dirt they can backwash out ). Automatic flush is not enough, as the accumulated dirt may increase pressure on the membrane causing it to fail. If your membrane is damaged, replacement is quite pricey. Does not filter chlorine, for those who may want to reduce our heavily chlorinated water for health purposes.

Hmm yes, slightly. More than sand filter. If your water pressure is at least 2 bar, it is fine.