iSpring F3 6-Month Prefilter Water Filter for Standard Undersink Reverse Osmosis RO Systems

I’ve been using iSpring reverse osmosis refill filters since 2018, and I couldn’t be happier with both the product quality and the customer service. The filters are consistently reliable, easy to replace, and maintain excellent water clarity and taste. I’ve noticed a significant difference in the quality of our drinking water over the years, and that consistency is exactly why I continue to reorder from iSpring. What truly sets this company apart, though, is their customer support — especially Nick. He has been incredibly helpful every time I’ve had questions about compatibility, replacement timing, or ordering the correct filters. He responds promptly, explains everything clearly, and genuinely cares about making sure customers are taken care of. It’s rare to find that level of ongoing support years after the initial purchase. If you’re looking for dependable reverse osmosis filters backed by outstanding service, I highly recommend iSpring — and if you get the chance to work with Nick, you’ll be in great hands. Read more

These work great and having to only change them once a year is absolutely amazing. Read more

Works great helps with taste of water Read more

Excellent product I'm happy 😊 Read more

It filters water, easy install. Read more

Cheaper but give me same level of filtration. I will buy again. Read more

I used the 75GPD Reverse Osmosis Membrane on a iSpring RCC7P-AK Boosted Performance Under Sink 6-Stage Reverse Osmosis system that I purchased in 2021. I replaced all of the stages including the RO Membrane after 8 months just to be safe (forever chemicals are a concern!). This said, the prior RO membrane was still performing at a good filtration. I had extra stages 4 & 5 so this review is for 1 - 3 (which was my purchase). 1-3 are super easy to install! Some likely other helpful info on my recent changes: 2/19/23 - RO filter change TDS Before change = 56. TDS after change = 20. TDS Tap cold =162. (65% before change, 87.6% filtration after change) 10/8/23 - RO fiter change TDS Before change = 43. TDS after change 38. TDS Tap cold = 297 (85.5% before change, 87% after change) I called Ispring (talked to Sean) to discuss TDS measurement and also to verify that the 6th stage was installed correctly as I recalled that the manual had a picture of it installed backwards (Red Stones are the inlet! which is the LH side for my system see picture above). Sean was super helpful, knowledgeable and friendly. He noted that its really important on 6th stage filters (with Alkaline Remineralization filter) to take the TDS measurement 30 seconds after running the RO faucet. This prevents a false high reading from the remineralization. He said an even better way was to measure the water coming out of the RO tank. This is easy just shut off the cold water inlet to the RO system and then the RO faucet water will be from the RO tank which is just prior to the 6th stage Alkaline Remineralization filter). Note: My feedback was for Ispring to update their instructions. Sean noted that's in work. Read more

These are working great. I'm on my 5th set and I replace them every 6 months. My plan is to keep cycling these until the faucet fails, but it's looking like the whole kit is going to make it 5 years. Read more