The replacement filter itself have the chip to calculate the time and water usage. 365 days of on time or 5,000 litres (whichever come first)

My household only got 4 persons. So I only replace the when reach 365 days during the machine start to beep. Like above forumer say, I usually delay 2-3 months to replace, I usually wait for PWP.

But if you need to replace every 6 months, mean your usage per year are as high as 10,000 litres. Maybe setup alternative cheaper filter to other usage. My usage for the filtered water only for drinking and my mom cooking purpose.

I got another friend attempt to cheat the digital monitor system by switching on/off everyday, means he only turn on when he want to use, well he did it without replace the filter even after 365 days. But around 2-3 years later, if my memory serve me correctly, his motherboard fried because of switching off/on daily. - as per claim by the technician.
3M got what. Condo or Landed?
That depend which model and how many budget you got. How many pax in your house? How often u use cold/hot water? Do you cook at home?

Get sand based external filter, look for FRP or Stainless Steel Vessel type. Flush yourself monthly, the media inside replace only 5-10 years range.

With your budget, you can go for branded one like 3M AP902 @ RM1k. If you don't need the convenient of 3M cartridge quick change, then you can opt for cheaper alternative like standard 20" double O ring big blue housing with pleated polyester cartridge.
This is a very interesting write up by hestati. Read it first before you decide your next course of action.
https://forum.lowyat.net/index.php?showtopi...post&p=87848869
5000 ltr over 6 months is 28 ltr per day. Quite unlikely for home usage (assuming it's not used for commercial purposes). I wonder why eSpring beeps for cartridge replacement in such short period of time.