When you buy a replacement membrane you will see ratings like 75 GPD, 80 GPD or 100 GPD. Picking the higher number is not always better. Here is what the rating means and how to choose the one that suits your purifier.
Quick answer – 80 GPD vs 100 GPD, which is better? Both give the same purity. A 100 GPD membrane only makes water faster, and it needs a pump strong enough to feed it. For most home RO purifiers, the best choice is the same GPD as your old membrane (usually 75 or 80 GPD). Choose 100 GPD only if your family uses a lot of water and your purifier has a 100 GPD pump.
What does GPD mean?
GPD stands for gallons per day – the amount of purified water the membrane can produce in 24 hours under standard test conditions (set pressure and water temperature). One US gallon is about 3.785 litres.
| Membrane | Rated output | Realistic home output* |
|---|---|---|
| 75 GPD | about 284 L/day | roughly 8–12 L/hour |
| 80 GPD | about 303 L/day | roughly 9–13 L/hour |
| 100 GPD | about 379 L/day | roughly 10–15 L/hour |
Which one should you choose?
- Replace like with like. The safest choice is the same GPD as your old membrane – the pump, flow restrictor and SMPS were matched to it.
- 75–80 GPD suits a small family (2–4 people) with normal water.
- 100 GPD suits bigger families or purifiers with a stronger 100 GPD pump, and fills the tank faster.
- High TDS / borewell water – choose a membrane specifically rated for high TDS rather than simply a higher GPD.
80 GPD vs 100 GPD RO membrane: which is better?
| 75 / 80 GPD | 100 GPD | |
|---|---|---|
| Purity (TDS removal) | Same class | Same class |
| Water output | Lower – enough for a family of 3–5 | Higher – tank fills faster |
| Pump needed | Standard 75/80 GPD pump | 100 GPD pump (a weak pump will not give full output) |
| Flow restrictor | Commonly FR 300 (75) / FR 400–450 (80) | Commonly FR 400–450 |
| Best for | Most domestic purifiers, normal family use | Big families, offices, purifiers built for 100 GPD |
| Price on our store | 75 GPD from ₹320 · 80 GPD from ₹435 | From ₹399 |
Our advice: do not upgrade to 100 GPD just because the number is bigger. If your old membrane was 80 GPD and the water output was fine, buy 80 GPD again. Shop 80 GPD membranes or 100 GPD membranes.
Match these three parts
| Part | Why it matters |
|---|---|
| Booster pump | A 100 GPD membrane needs a pump that can deliver enough pressure and flow. A weak 75 GPD pump will not get full output from it. |
| Flow restrictor | It controls the drain water. Commonly FR 300 is used with 75 GPD and FR 400–450 with 80–100 GPD. A wrong restrictor either wastes water or chokes the membrane. |
| Membrane size | Most domestic purifiers use the 1812 size. Check that the new membrane fits your housing. |
Does a higher GPD mean purer water?
No. GPD is about quantity, not purity. Purity depends on the salt rejection of the membrane and the condition of your pre-filters. A good 75 GPD membrane can give lower TDS than a cheap 100 GPD one.
Popular options on our store
- 75 GPD membranes – for compact domestic purifiers
- 80 GPD membranes – common replacement size
- 100 GPD membranes – faster filling, larger families
- 300 GPD membranes – for light commercial units
Frequently asked questions
Can I put a 100 GPD membrane in a 75 GPD purifier?
Usually yes if it fits the housing, but you may need to change the flow restrictor, and you will only get the extra output if the pump is strong enough.
Is 80 GPD better than 75 GPD?
Slightly higher output, same purity class. The difference in daily use is small.
What is the difference between 75 GPD and 80 GPD membrane?
Only the rated output – about 284 vs 303 litres a day under test conditions. Purity and size (1812) are usually the same, and in daily use the difference is small. Most 75 GPD purifiers can take an 80 GPD membrane.
How long does an RO membrane last?
About 1.5–3 years in most homes. See when to replace an RO membrane.
Need help choosing the right part? Send a photo of your RO or its model name on WhatsApp (96252 23245) and we will tell you exactly what fits.
Need the right part for your RO?
Original filters, membranes and pumps at wholesale rates. Send us a photo of your RO – we will tell you exactly what fits.
