Seachem Matrix is a special media as you will be able to grow beneficial bacteria colonies that will consume ammonia, nitrites and nitrates. So, do you need to put these hollow stones in a bag? You can find out in this article from Aquarium Blueprints.
Will Seachem Matrix sink in your fish tank?
Most of the Seachem Matrix will sink right away if you decide to drop them into your fish tank. While a few stragglers may stay afloat, these will eventually start to sink as well once they get waterlogged.
If you want all of the stones to sink immediately, without using a bag, then we recommend pre-soaking. By doing so, you should be able to get the small rocks waterlogged in addition to rising off any dust particles that may other cloud your aquarium.
What are the benefits of putting Matrix in a bag?
By putting all of the Matrix pebbles in a bag, you will be able to easily remove the media from the fish tank for cleaning. For the uninformed, we recommend that your rinse these stones every time you do a water change so that the pores don’t get clogged up; otherwise, the beneficial bacteria living inside the powers may end up dying.
When rinsing the Seachem Matrix, make sure you are using the water you are planning to take out of your fish tank. If you use tap water instead, then the chlorine or chloramine chemical compounds from it could end up harming the beneficial bacteria living on the surfaces.
By using a bag, you will also prevent the pebbles from getting lose in your filter. The pebble could end up getting stuck in some areas, such as the output nozzle or impeller, causing water flow and/or pumping problems.
One last benefit of using a media bag for Matrix is that you can put the filter media directly inside your tank. You can even use the media as a substrate. As we stated above, clumping all the stone into one bag will make it easier to perform maintenance to the media.
Can you use Matrix without a bag?
If you already have a media compartment in your filter, then it may be good enough to hold all the Matrix stones in place. In that case, a bag isn’t really needed, especially if you can remove the media compartment as a while for maintenance.
In every other situation, we recommend using a bag as it makes it easier to remove Seachem Matrix for cleaning, which we recommend doing every time you do a water change.
As for what types of bags you can use, we recommend getting filter media bags as these should be safe for aquarium use.