QUOTE(kimhoong @ May 21 2018, 05:44 PM)
Besides that, you mentioned about industrial standard size - can you show some examples on the alternative filters?
For stage 2, there is nothing equivalent for now, except Disruptor from say USWaterSystems, but I'm sure it is coming soon by other brands.
For stage 1, there are plenty of NSF certified melt blown filters by Taiwanese companies or by Pentek or Omnipure. Pentek has NSF pleated cartridges as well.
For stage 3, again, Omnipure, Filtrex Green or MatriKX, however,
be very careful with MatriKX. There used to be plenty of fakes of these filters, and they still are out there, I see them on Lazada. KX was recently bought by Warren Buffet and they moved all production outside of USA, as far as I know they completely stopped producing carbon blocks in USA and now make them mostly in India, some in Singapore. US suppliers bought all remaining stock of US made cartridges, but even that is now gone.
Another beauty of the universal system is that say you want to upgrade to RO (I mentioned it before) without tank. Then all you do is sediment+carbon+carbon, then just add 400GPD membrane on top and you pretty much have tankless RO system. Or let's say we start using chloramine in Malaysia (hope it never happens, but still), replace stage 3 by chloramine cartridge and you're set. Or let's say you decide you don't want fluoride, then simply upgrade stage 3 to bone char carbon block.
All that is easy to do with standard system, in case of say Aquaphor or Aquasana or 3M or pretty much any other system, you will have to buy pre/post filters instead of replacing cartridges, and these are not cheap, unless you go for some from local hardware shop. But then you have NSF filter for 1000RM+ with who-knows-what post filter housing/fittings/tubing.