There are a lot of great filtration media products on the market. You could easily run several of these at a time and have crystal clear water with low phosphates, nitrates, and no ammonia.
But I would urge a bit of caution. Oftentimes as beginners, we are quick to panic. We see unwanted algae growth and we immediately assume we need a phosphate remover. Or the water is a bit cloudy so we set up a carbon reactor.
I’m not saying that filtration media is bad, but that it is important to use sparingly so as not to strip the water of essential and trace elements. Don’t let filtration media become a crutch, but rather keep up with your water changes, make sure you have enough live rock, and don’t overstock your tank.
You don’t need to have a reactor for filtration media, as you can place most items in a mesh bag and place it in a high flow section of your tank. But, things like activated carbon and GFO will work more efficiently in a reactor.
Here is the basic breakdown of filter media in this list:
- Activated Carbon – great for removing unwanted odors, medications, heavy metals, and unwanted colors that may keep your water cloudy.
- GFO – used for removing phosphate from the water. A more natural approach would be to set up a refugium with live macroalgae.
- Ceramic Media – comes in balls, bricks, and plates, depending on the type, used as a biological filter to remove ammonia, nitrites, and nitrates.
- Poly Filter – a combination of mechanical filter pad and chemical filtration to remove ammonia, heavy metals, and phosphate.
There are many, many more types of filtration media out there, but some of them require a bit more advanced understanding of this hobby, and you will likely not need to use them for a while.
Personally, I will throw in a bag of activated carbon once every other month. I keep it in for a couple weeks and then remove it. It helps to make the tank smell fresh and really polishes the water.
I try to stay away from GFO because I figure if I have an algae problem, then something is out of whack in my tank whether it be over feeding, too much light, or not enough snails!
5. Mesh Filter Bags ~ $5-$10
I think mesh media bags are perfect for a beginner. Will a media reactor work better for certain types of media such as activated carbon and GFO? Of course. But a media reactor takes up space, and for a lot of us we don’t even have a sump!
The trick for getting the most out of media bags is placement. If you just throw it at the bottom of your rear filtration chamber or sump, in a corner where the water hardly even moves, then you may as well not even bother.
Media bags only work when placed in a high flow area where water is constantly flowing through.
There are two types of media bags here. The one on the left if a more coarse weave and is better for larger items such as ceramic bio media and Matrix.
The fine mesh bags on the right are great for activated carbon and GFO.
4. GFO
What is GFO you may ask? Click HERE to learn more!
When I started out in the hobby I would constantly run GFO, and I quickly upgraded to the high capacity type! I figured, “If phosphates grow unwanted algae, then why not get rid of it all!”
Well the funny thing was, no matter what I did, I couldn’t stop the nuisance algae from growing. So clearly phosphate was not the issue.
And nowadays, hobbyists are actually trying to keep a small amount of phosphates in their tanks due to the belief that it is beneficial to coral.
I think GFO is best used as a stop-gap measure. If your phosphate is spiking for some reason, then sure, go ahead and throw in a bag of GFO for a short while until you can regain control. But I wouldn’t recommend GFO for long term use.
The regular GFO on the left will work perfectly well for most beginners. The GFO on the right is high capacity (HC), and can absorb twice as much phosphate. I would only use this if you have a larger system (above 60 gallons), but don’t have a lot of extra filtration space for lots of GFO.
3. Poly-Filter ~$25

The Poly-Filter is unique amongst all filtration media. It is a brand-name product and to my knowledge they are the only company to make anything like it.
I don’t even know how it works, but I have used it in the past and it’s great. It comes in different sizes, and then you just cut it to fit your filter.
The Poly-Filter combines simple mechanical filtration (sponge) with chemical filtration. It is color changing, and the color changes depending on what chemical is being absorbed. It can absorb ammonia, heavy metals, medications, and phosphate, so they have to have some sort of carbon/gfo in there right?
It is a bit on the spendy side, but I know some hobbyists who swear by this stuff.
2. Ceramic Bio Media
As long as you have enough live rock, maybe some live sand, and don’t overfeed or overstock your tank, you will probably never need ceramic media.
But unlike GFO and activated carbon, there really is no harm to adding ceramic bio-media. All it does is allow more space for beneficial bacteria to colonize thus helping your biological filtration capacity.
A lot of hobbyists utilize ceramic media if they have a heavily stocked tank, or if they don’t use or use enough live rock for their bioload.
Ceramic media comes in different shapes and sizes, and is usually placed in a sump or rear filtration chamber.
The only thing to take into consideration is whether or not a specific biomedia is designed to remove nitrate. Nitrate removal depends on anaerobic bacteria, and some biomedia is designed to host largely aerobic bacteria. So just read the label before making a purchase so you know what you are getting.
1. Activated Carbon

There are several different shapes, sizes, and types of activated carbon, but I’m only going to recommend ROX 0.8. Different companies make ROX 0.8, so it doesn’t matter where you get it from.
ROX 0.8 is the top of the line carbon. It is less dusty and absorbs colors, metals, and odors better than the rest. It is also the most expensive carbon out there!
I used to run carbon all the time on my tank, thinking it was the reason my water was fresh smelling and clear. But now I hardly run it at all! I’ll add a small bag of ROX 0.8 carbon every other month or so, just to polish the water a bit. But I only leave it in for a week or so!