Coralife BioCube Aquarium Fish Tank 1" Bio-Balls for Sump Filtration

I've ordered these twice and both times they were definitely 5 gallons or there just about; we checked by dumping them in a five gallon bucket and it's close. I attribute the just shy of the line because when they connect to each other it reduces the space.They are 25 mm, just short of 1 inch, which means they are essentially the size they say they are. Not sure why people were expecting bigger than an inch.My only gripe is that they are definitely "airier" than bio balls you get at a pet store but when they are a tenths of the price I can't complain too much.All in all a great product for a sump/pseudo big filter. Would definitely recommend to get these instead if you need bio balls are were considering going to a big box store.

These bio balls are awesome. I have used them before and got another 5 gallons for a wet/dry filter I am building. The price is really good and I am using a 20 gal long to build my sump and 5 gallons fits really nicely. The sump will be for a 125 gal tank and it should work great. There are other cheaper bio materials, but I like using the actual bio balls so I have some piece of mind that the product will work correctly and they have so far.

This is my favorite filter media to use for both my fish tanks and ponds. They are easy to maintain and do an excellent job at keeping my water clean and safe. I use them in overflow, canister and sump systems. My tanks range from 27 to 220 gallons and the pond is 2,000 gallons. All of them function very well with this media. I did have a couple of partially broken balls but that is to be expected. A couple out of hundreds is no big deal. Highly recommended!

7 Gallons of these and 3 gallons of Pond Matrix should keep my turtles happy, they are small, but i see no downside.

I would offer that the seller needs to redo the description of the amount of Bio Balls they are selling. 5 gallons is a misleading description. Integrity should count! This is NOT 5 gallons of Bio Balls. Maybe 2.5 gallons at the most. I have a 300 Gallon Saltwater tank with a very large sump, requiring a large amount of Bio Balls, which is why I purchased from this seller. I will not make that mistake again. I would recommend perspective buyers to look elsewhere for bio balls and give your business to a seller with integrity.

Crazy how many there was when I opened the box, my grandson enjoyed the fact that he could stick them together like legos.

Too small in diameter.

great price, good product.