SeachemMatrix, 4 L / 1 gal.

I have used Seachem Matrix for well over a year now, and I can say for a fact that it is by far the best media out there, and the results I have had using it prove it.Every bio media will give your filter the surface area to grow aerobic beneficial bacteria that convert ammonia and nitrites into nitrates. What's so special about Matrix is that each piece of the bio media is so porous yet dense that there are nooks and crannies in each piece that a special type of beneficial bacteria is able to grow, specifically anaerobic bacteria. This anaerobic bacteria consumes nitrates. This type of beneficial bacteria is one that can only grow in environments that are not oxygenated (which is why the porosity and nooks and crannies Matrix bring to the table are important).I keep African Cichlids (Mbuna specifically), which have a reputation for being some of the most demanding fish when it comes to bio load. I keep the tank stocked moderately, overfiltered, and chalked full of as much Seachem matrix as I can fit. Before switching to Matrix I was using the typical ceramic rings and doing weekly water changes. My Nitrates would get up to 30-40 PPM after 1 week with no ammonia and no nitrites. After switching to Seachem Matrix and giving the anaerobic beneficial bacteria a couple months to establish itself, it is a night and day difference. I test my water weekly. I was shocked to begin seeing a decline in the numbers on my nitrate tests. Probably around the 6 month mark or so, there began to be such a little amount of nitrates that I could skip water changes. I keep everything recorded in a spreadsheet and there was one point that I went 2.5 weeks without a water change and my nitrates were only at 25 PPM, KEEP IN MIND THESE ARE FULL SIZE MBUNA WITH NO PLANTS IN THE TANK. I still do weekly water changes and test my water weekly, but typically there is so little nitrates that it wont even register on a dip test strip and API registers between 0 and 5 PPM. Truly amazing.The proof is in the pudding, Seachem Matrix makes big claims and much like every other Seachem product, it backs them up. 10/10 would recommend, I will never run another bio media in any tank.

Excellent quality product 👌

Great product working well for my large aquarium

This review is meant for both Seachem's Stability and Seachem's Matrix.I helped my son set up his 120 gallon African cichlid tank. We went through about 5 or 6 different filters and settled on an Eheim. From what we had learned from our research on tank setups we had understood that the filter media, once properly colonized, will remove ammonia and nitrites from the water but will not remove nitrates (ammonia gets converted by one kind of bacteria in the filter to nitrites and in turn another kid of bacteria will convert the nitrites into nitrates). The only way to reduce the nitrate levels is by either having live plants or even better, periodic water changes. We were also told that if we have a deep enough substrate then after about 6 months or so, if we get lucky, deep in the substrate will develop a bacterial colony that will help reduce the nitrates.As I continued my research I stumbled on to the Seachem web site. I was impressed by the specs of their Matrix product. It claimed to be able to support bacteria that will eliminate nitrates from the water. Great! Now all I have to do is buy this filter media, wait six months and I'm all set. Not only that, but from what I've read on the Internet, it could take up to two whole months for the ammonia and nitrites eating bacteria to properly develop.Well, luck for me, I found the Stability product. I added both the Matrix filter media and Stability to my setup (Stability needs to be added to the water on a daily basis for one week) and tested the water after one week. I was pleasantly surprised to see that the ammonia and nitrites levels had dropped down to 0! My son was telling me not to bother testing for nitrates because it's guaranteed that they'll be there. I tested anyway and guess what? Zero!This works like magic!

Keeps the water quality where I want it in the turtle tanks.

Use this in my fx6 canister filter keeps my saltwater tank crystal clear

When I first took a look in person of Seachems Matrix Bio Media it really just looks like porus pummice rocks. My bucket was filled with all different sizes from 1/4 inch all the way up to 1 1/4 inch. It doesnt look like they sorted out all the rocks in my 4 liter bucket thoroughly as it seems there is a few assorted rocks in there. Some of the assorted other rocks look like plain grey garden/road gravel, some red gravel, some jet black non porus rock resembling obsidian, and other weird rocks that made it in my bucket. Not a big deal though since the "other" rocks were few and far inbetween. The matrix seems to be doing its job fine and I really like the bucket that the 4 liter Matrix comes in LOL.There is a little discrepancy though. If you find their article (Google or Bing)on how great they are (they did their own independant studies), and how much better they are than the other products such as Eheim Substrat Pro. They have their surface area listed way higher than what they list on the packaging. The packaging lists Matrix as having 170 square feet of surface area per liter, while Substrat Pro lists their surface area as 450 meters squared per liter!That makes Eheim Substrat Pro the clear winner with 4,843.75968765 square feet of surface area for bio bacteria to colonize. Though online in their article they say they have 10 to 20 times the surface area of Eheim substat pro? You can even find listings where they say they have ~700 meters squared of surface area per liter. Which surface area per liter for matrix is the correct listing? Very confusing (are they trying to confuse and trick us into buying their product?). It works fine though and is much cheaper than Eheim substrat pro. I still like substat pro better because they have ONE listing for their surface area per liter and it looks much cooler (like KIX cereal). Matrix honestly is just a bunch of porous pummice rocks... but they work fine.