RO Replacement Filters South Africa
When to Replace Your RO Filters
Your reverse osmosis system has multiple filter stages, each with a different replacement cycle:
| Filter Stage | What It Does | Replace Every | Monster Product | Price |
|---|---|---|---|---|
| Stage 1: Sediment Pre-Filter | Removes sand, silt, rust particles | 6 months | 10" Sediment Cartridge | R59 |
| Stage 2: Carbon Pre-Filter | Removes chlorine before membrane | 6 months | 10" Carbon Block Cartridge | R129 |
| Stage 3: RO Membrane | Removes 95-99% dissolved contaminants | 1–3 years | 75GPD RO Membrane | R495 |
| Stage 4: Post-Carbon Filter | Final taste polishing | 6–12 months | Included in filter pack | — |
| Stage 5: Mineral/Alkaline (if fitted) | Adds minerals back | 12 months | Check compatibility | — |
Signs Your RO Filters Need Replacing
- Water tastes different or has an odour
- Flow rate has noticeably decreased
- TDS reading is higher than normal
- It's been more than 6 months since last change
- Water appears cloudy or discoloured
RO Filter Packs — Buy the Complete Set
RO Annual Replacement Filter Pack — R595
Includes all pre-filters and post-filters for a standard 5-stage RO system. Replace every 6–12 months depending on water quality and usage.
🔄 Set a reminder: Replace every 6 months for best water quality.
RO Membrane Replacement
75GPD RO Membrane — R495
The membrane is the heart of your RO system. Replace every 1–3 years, or when:
- TDS rejection drops below 85%
- Flow rate drops significantly even with new pre-filters
- Water quality test shows elevated contaminants
How to Check If Your Membrane Needs Replacing
- Test the TDS of your tap water (inlet)
- Test the TDS of your RO water (outlet)
- Calculate rejection rate: (1 - outlet/inlet) × 100
- If below 85%, replace the membrane
Product: TDS Meter / Water Test Kit — R249
Compatible Systems
These replacement filters fit standard 5-stage RO systems with 10" housings. If your system uses non-standard sizes, contact us for compatibility advice.
Frequently Asked Questions
Q: Can I just replace the membrane and not the pre-filters?
A: No. Old pre-filters let chlorine through to the membrane, which damages it permanently. Always replace pre-filters on schedule.
Q: Are all 10" RO filters the same?
A: Most standard RO systems use universal 10" x 2.5" cartridges. However, some brands use proprietary filters. Check your system manual or contact us.
Q: How do I know which filter pack fits my system?
A: If you have a standard 5-stage under-counter RO system, our RO Annual Replacement Filter Pack will fit. For non-standard systems, send us a photo and we'll confirm compatibility.
Monster Mechanical — your recurring filter replacement partner. Never forget to replace your filters again.