wat is the difference between 3m and the traditional sand filter for external filtration?
looks like the cost of maintenance for the 3M is high where you might need to replace the filter every year at rm399 where the sand replacement might be rm250 and only need replacement every 3 years or more.

and for the indoor filter, RM650 sounds reasonable compared to others but the rm180 for catridge replacement every 6 months might be costly.

im not saying anything bad bout 3M and i quite like it but i juz want to know the money worth spent.

please advise as Im looking for a reasonbable water filtration system