2Pcs Aquarium Cube Filter, Activated Carbon Aquarium ​for Ponds,Fish Tank,Stock Tank for Horses,4X4X2 Inch，eco Aquarium Water Purifier Cube.

I use it for my horse trough. Don’t be fooled by the other website. Those are fish tank size and costs more. These are good size but remove before washing the tank because they are fragile.

These have been in my water for a week now and the water is nasty!Will never buy again!

I don’t understand how these work but they are magic! Keeps out turtle tank crystal clear! Best money I’ve spent!

A friend in the pool industry recommended that I put 1 of these in each of my horse water troughs. We had a massive problem with algae and silt from the well but did want to use the soft water off the house.I added ONE of these to each 250gallon Rubbermaid trough and have never had such clear water.It has been an inexpensive way to keep throughs clean and free up my time for other projects.See the pictures from before and I will add some of after.

Nice product! Highly recommend!!

On my first order, the items arrived all chipped up and broken in the box. I had high hopes for these so I requested a replacement pack so I could give them a fair shot to see if they work.The replacement items were also dinged up but I out them both in my troughs / stock tanks because the hassle of returning for a moderately low priced item isn’t worth the drive to UPS or Whole Foods.This morning while out feeding and checking the tanks, I noticed particles floating around. Plastic pieces from the rapidly disintegrating filters. Don’t want any animals ingesting that.Unhappy now that I can’t find a return / refund option for the replacement pack.Live & learn. Cheap foreign made garbage.

helps keep it clean but the block falls apart in the water which can’t be good for the animals to drinkso this last block i am putting in a mesh bag to eliminate that issue

I have a tank of guppies and once in awhile it needs water change. I just drop this puppy in and the fish swim straight to it. They play in the bubbles. But this charcoal brick is worth the money. I recommend because it truly works. Thanks manufacturer's and all involved it getting my water clean and clear again. 👌 my fault because I don't do partial water changes regularly. My aquarium however is all natural.