Stone Natural Volcanic Water Clarifier and Odor Remover Rock for Aquariums, Nano, 2-Pack

Took a chance on these after reading conflicting reviews. Rinsed them in tap water, let them soak for a few hours (reviews say 24-48 😬), and plopped both blocks into my betta son’s 3.5 gallon tank.On a scale of 1-10, my tank was a 3.5 on the cloudy scale pre-blocks, and 24 hours following slapping these puppies in there, it’s a 0. Clear as crystal.They work. Nothing else shifted in my tank, the only explanation is that these tiny little miracle bb’s did the job.Get ‘em. Rinse ‘em. Soak ‘em. Then let ‘em clean your cloudy filth.

So impressed with how well these work! I was changing my turtles water daily bc of the smell.

Ok first off, I read the instructions and then I totally didn't follow them because I'm stupid lol. That said, I'm so glad nothing happened to my fish lol. I've only been using this for 3 days now and it seems to be harmless for the fish. Especially since I didn't wash the cubes before hand. I just through them in the tank. I know, my bad. Anyway, the water seems to be clearing up. I scrubbed the glass before putting the in but hopefully this will help keep algae from growing again.Update!It's been weeks now and the algae has gotten worse. These did absolutely nothing to help. I ended up getting some liquid from the pet store to help control the issue and it has worked perfectly. Huge difference within one day. I highly recommend getting something from the pet store not these stones

I'm rather amazed that this did work as advertised. I tried many things previously with poor results but 9 months later the aquarium is still clear and water changes were far less necessary.

Awesome

I bought these for a 3 gallon beta tank. It was clear when I added them after a fresh change and it said they would keep it clear…it made the water cloudy instead. It also made the things in the tank feel slimy when I took them out! I left them in for about 5 days and started to worry about the health of the fish! Afterwards I removed them and did another water change! Thanks for junking out my tank! I changed the water and it was Beautiful, so I added only 1 back to the tank! 24 hours later it was Cloudy again! It’s NEVER been like this before! I usually do a 50 % change every 2 weeks. It might get only slightly cloudy but I like it perfect. I hope it doesn’t kill my Betta! My cat is going to be mad, it’s his fish! I’m returning this garbage… YOU have been warned!

I have one in my betta tank. It's helping keep the tank clean.

These eco-blocks are great for your fish tank especially when they’re cloudy as you can see the picture above my aquarium is still cloudy. When I first put the block in there you could barely see it after two or three days it’s cleared up quite a lot. I say two more days and it’ll be crystal clear water again. I’ve done water changes and all that like I said, and it still comes cloudy with that eco-block it’s giving off minerals and all that other stuff as long as you keep it by Bobo for some reason and it works great.