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

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.

I needed something to help keep my 3 gallon tank clean. Yes, I have an air filter and a filter unit; but goldfish are known for a lot of waste. Before I had these stones, I would do a 50% water change and it would bare last four days before I had to clean it again. Now, the water stays clear for a week. I am amazed and really happy to have found these. Totally worth the money!!

Tank is still getting so much algae even with these.

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.

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

Work great

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.

After reading the reviews, I thought that it was too good to be true. My tank of almost two months was cloudy as hell and we had tried all the stuff that we were supposed to do when getting a new tank. Nothing seemed to work. So once again I cleaned out a percentage of the tank water, sifted out the old muck, added new conditioner like Ive done before but the difference this time was adding the stones. My husband came home after a few days and he said, "well I hate it to say it but for as pricey as those stones were they certainly did the trick." After only less than a week our tank looks 80% better and we have less stones than necessary since we have a 20 gallon tank. I will continue getting these for my tank in the future.

A bit pricey but these really work so worth it if you want something natural and low maintenance to help keep your tank clear and clean.

I added these two cubes to my 5 gallon tank and it made no difference to the slight cloudiness I was trying to dissipate.