I had some difficulties with my MSR filter on my last backpacking trip a couple months ago, I asked the other hikers what they were using, the majority said one of the Sawyer filters. (Mev above also suggested Sawyer.) A couple of them were using Sawyer filters with Evernew water bladders that had a thread pattern that matched the Sawyer filter.
I bought a Sawyer similar to the mini at the link below but the version I got was threaded at both ends for use with a gravity system.
https://sawyer.com/products/mini-filter/
I bought a couple Evernew bladders and a Sawyer Mini on Amazon. Tried it once with tap water, appears to work great. Have not tried it on a trip, but I suspect as long as you periodically backflush it, that it should work well. At the video at the above link, they mention backflushing it.
There was a thread on this forum some time back, someone did not backflush his sawyer, put it in storage, then months later took it on a trip and it did not function well. I ALWAYS test my gear before I take it on a trip, pitch the tent to inspect it, make sure my liquid fuel stove works (but I do not bother to test butane stoves), and test my water filter while at home.
If you are concerned about viruses, after you filter the water you could add a couple drops of Chlorine bleach per liter, let it sit a half hour. I usually skip the Chlorine but I carry a small one ounce bottle with a flip top dropper in case I have a reason to be concerned.
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Some people swear by Steripens, I have never used one. You might want to research them too. I bought one for a trip, but never needed it on that trip. Have not carried it since.