I don't think I got counterfeits since the ones I ordered were sold and shipped by Amazon, however they are terribly defective.

I have been using these filters for over a decade and this is the first time it has been this bad. After getting excessive charcoal after doing my normal pre-rinse I have tried everything up to and including blasting them with an extremely powerful garden hose attachment that would hurt pretty badly if you sprayed it direct on your arm. Not the level of a professional pressure washing kit but pressure that is not found in a typical hose attachment. These are powerful jets in a commercial set up that would probably disintegrate the filters if left in a stream instead of being diffused as a shower. These hoses can strip cat poo off of any surface from 25 feet away..

No matter what I do the charcoal appears in the fountains in less than 24 hours. I have tried all the units in the kit and all are the same. I hope it's a bad batch and not an indication that a lower quality filter has been adopted. The pictures were taken less than 18 hours after extensive attempts at flushing. There is no user error in place here. I have maintained several Pioneer Ceramic fountains for a long time now. I am intimately familiar with the product.

In fact, I spent 3 years hacking these filters by opening them up and replacing both the charcoal and pre filter media with with pieces I cut from large sheets. Our rescue got too big so I did not have the time to keep up with it. However, since I won't use these any more I have already started cutting again so If I have to do it long term due to changes in manufacturing I most certainly will do so. I'm one of those freaks that think most cats are better than most people. Working with emergency rescue cats is a tough and tearful job. I'll be damned if I'm going to let a crappy filter become acceptable. These cats need pure, clean water that's free of particulate - ESPECIALLY visible particulate!

If anyone is curious, the cost of the hack is about 30 cents per filter. For 30 cents you get absolutely perfect filters that are more durable and generous than these OEM's have ever been. When you take the time to make your own - properly - you immediately realize what a complete rip off these replacements are. If we did not have an average of 15 cats at all times with about half being clinically critical at our facility I would never have gone back to these flimsy refill filters.

One filter case, if you are careful with the plastic, will last years. If you are a regular household cat owner or even multi-cat home, once you have a few filter cases on hand to dissect you can, and probably should, fire Pioneer with respect to this faulty replacement media. Your homemade filters will only cost a mere fraction of these, plus, the filler will both last longer and produce much healthier H2O for your kitty. Don't tolerate shedding filters. While not toxic, charcoal is an irritant and not something that people or pets should consume on a daily basis.

I'll tell you, I love my metal Fountain. My cat has one of those chins that gets packed me from the plastic fountains. Plus let's face it unless you fill it with filtered water you're going to end up with a little bit of gummy stuff on the edges. So the stainless steel cleans up really nicely. I'm loving the subscription that Amazon offers, I just put this on every 3 months for the packet of three and now I make sure I change it on the 1st of every month. Pretty cool

They fit the Pioneer Pet fountain I have perfectly. They snap on so easily and are great quality. I have bought these multiple times and as long as they are available for purchase, I will continue to buy them. The price is great, walking to my mailbox is so much more convenient than a trip to the pet supply store and my kitties have a never ending supply of fresh, cool, clean water bubbling up from their fountain. Make sure you follow the directions and rinse them first so you don't end up with charcoal dust in the fountain. It will not hurt your pet but they deserve to have dust free water.

Can't recommend this one. Rinsed first filter as suggested and it leached charcoal day 1. Another reviewer suggested soaking a filter overnight prior to first use -same result leached charcoal day 1. Filter housing has no holes in the bottom to pull water through & charcoal builds up in the bottom of the housing too.

Update:
Found what seems to be a solution for the charcoal dust going everywhere. Wrap this filter in a paper coffee filter. It's been several days now and no charcoal dust is visible at all in the bowl. Manufacturer should be able to address this issue by wrapping the foam/charcoal inside the filter housing.

Great filters. Last quite awhile, and are easy to change out in the Pioneer Pet fountains. No complaints! Arrived quickly and in great condition. Just make sure you rinse them thoroughly under water to avoid getting charcoal bits in your fountain. I think they suggest changing the filter every 2 weeks, but in my experience you can stretch them to 3, possibly 4 weeks. If you live in an area with hard water (like I do), I definitely suggest putting filtered water into your fountain. It'll make your filters (and your pump) last longer!