How do I change the filter in my aquarium without losing bacteria?

In home aquarium system, the responsibility of keeping aquarium ecosystem well maintain falls hobbyist, and this often means changing out the filter for fish tank regularly. If you want to save time and money by keeping the good bacteria in filter around, you are going to want to know the different ways of changing filter without losing them.

Keeping the Old Filter Temporarily

A stark change in a complete filter change can make a significant difference in the fish’s environment, so you are going to want to minimize how much of a difference it makes. One of the best ways to do this is to keep the old filter in the tank along with the new filter. You will want to keep the old filter in the aquarium for approximately a month to allow for all of the good bacteria you have built up to move and transfer over to the new aquarium filter. This way, when you do remove the old filter, you will still have a good amount of bacteria in the new one to ensure that there isn’t a significant change that would end up affecting the health of your fish and other aquatic animals. With this method, the main area you will want to pay attention to is the flow rate. You want to make sure that the flow rate stays in the same range that your fish need, as having two filters can affect the flow rate sometimes. If the flow rate ends up becoming too high because of it, there are filter pads to bring it back down to a comfortable level for your fish.

Keeping the Old Filter Permanently

If you want to have an even stronger supply of good bacteria, as well as a backup plan if one of the filters ends up not working, you can actually keep the old filter with the new one for as long as you need to. There is technically no reason to keep it in longer than one month, as this is the time it takes for the bacteria to grow and adjust, but there are some benefits to doing it this way. For one, you won’t have to worry about there being a shock to your fish because of the removal of a filter. In fact, now, if one of the filters breaks down, there’s a good chance that you will have more time to deal with it because the other filter will be able to function. As long as the cartridge isn’t completely broken, you can keep the old filter in as long as you want to, even permanently, as long as having two filters doesn’t affect the flow of the water too severely.

Just Replacing the Filter’s Media

This method tends to work out the best for people who need to remove the entire filter because something broke or because a new one is considerably better for the fish in the tank. Most of the bacteria that your fish will benefit from are going to be in the filter’s media, meaning that if you choose to just keep the old media of the filter and transfer that over to the new one, you won’t be losing nearly as much of the media in the new filter. The main thing to look out for with this method is that the filter you are moving the media to needs to have the same sized area and shape for the filters, otherwise they may not fit. If the cartridge for the media is falling apart or severely damaged and you need to replace it, you should keep it in for about four to six weeks before fully replacing it, just to ensure that the bacteria are able to grow properly in the new filter.

Colonizing the New Filter

This method works best for people who don’t want to have two filters running at the same time and is good for when the old cartridge won’t fit in the new filter. This is generally the last option to consider if you want to preserve as much of the bacteria as you can, and it may take a little bit of time. You will want to take out the old filter and look at its cartridge. If it is in good working condition, you will want to place it in the aquarium with the new filter. If the media is not falling apart, this will work much the same way as fitting the entire cartridge into the new filter. In approximately one month, the bacteria will have made its way into the new filter. You should remove the old cartridge shortly after this, as it can cause problems after a month passes.

Using Even Part of the Filter Media

Another consideration to make is that if you don’t have enough room to use both the old aquarium’s cartridges, you can mix the media for them so that at least some of the bacteria gets into the new filter’s cartridge. This isn’t the best method to go with, but if you have no other options, it can make the transition easier. For this, you will want to take a portion of the media from the existing filter, whether that is some of the sponge, ceramic rings, or anything, and you will simply want to place it inside the new filter’s media area. This way, you will get some of the bacteria from the old filter into the new one, which will ensure that your fish will be able to bear the change of the new filter. Ideally, you would want to let both filters run for at least a week after doing this, as this helps your fish out tremendously.