Finest-Filters 500g Ceramic Filter Rings Biological Filter Media in Bag for Aquarium/Pond Filters

If you find this review useful, it'd be great if you could click the appropriate button below. :-)----------These are great ceramic rings - and wonderful value for money. The 500g bag is big - big enough that I could split the rings between a regular 60l tank and a 12l 'nano' tank. Within a couple of days, I could see that they were developing colonies of bacteria. A few weeks later, nitrate and nitrite levels in both tanks are at zero, and the rings seem to be doing their thing.

Very large bag, it meant that I was able to split it into multiple uses!I did rinse them off first and not much dust came off them which is good.They work well in the tank and I’ve not had any issues

Probably the best value on Amazon for the amount you get. I actually underestimated how much 500g is an ended up with a bag too big for my tank. I cut the bag, poured some out, re-tied it and now it is spot on. Good bacteria are manifesting themselves all over already and keeping things in my tank very stable.If you have a big external filter I would highly recommend these. Just make sure you give them a really good flush out before you put them in. I rinsed them off but probably should have rinsed whilst shaking them a bit more to get rid of the dust. My water looked a little gritty for the first few hours.

Excellent product fab quality

Value but large wouldn’t fit all filters. They fit my fluval 4 which I was unsure about. Nice zip up bag inside plastic bag. I’m pleased.

I've only got a small tank, so needed maybe 1/4 if the bag, but it means I've got spare if needed. They work exactly as intended, none came split or cracked, and they have developed a nice biofilm so are working as they should.

These are small enough to fit into my internal filters, alongside some sponge. The ceramics keep the sponge in place and provide a good surface for microbes.

Ok does the job.