Can you overfilter an aquarium

When you're new to fish keeping, you want to buy every fish you see. But there is a limit to how many fish a new aquarium can hold, regardless of how large it is or how efficient the filter is. Many fish grow larger after they are purchased, and some fish are territorial and become aggressive when crowded with other fish.

Always err on the side of having fewer fish in your aquarium rather than too many. It's normal to worry about your fish going hungry, but you can cause more harm by feeding too much. A new aquarium should be fed once a day , and all food should be consumed within two minutes. Uneaten food can pollute the water and cause ammonia and nitrite levels to rise.

Buying a filter that is too small. You can't really over-filter an aquarium, but it's fairly easy to under-filter one. Most aquarium filters are rated according to how many gallons the aquarium holds.

This rating system works well for the most part, however, heavily populated aquariums, or those with large predatory fish or fish that generate large amounts of waste should be fitted with oversized or multiple filters. For best results, purchase a filter that is rated for an aquarium a little larger than the one you own.

Seeking advice from too many sources. It's important to research equipment and livestock purchases before making them but asking the same question of a number of different "experts" can sometimes result in confusion because everyone has a different opinion or method for success. When you're new to aquarium keeping, it's hard to know what techniques will work best for you.

Stick with one reliable source of information at first, and follow their advice until you feel confident enough to try things on your own.

Compromising quality for price. Before adding a second filter, you can do some homework as to what water conditions your fish prefer. Adding baffles is a simple and effective way of reducing flow, even with using two filters. It is vital to have some biological filtration in your aquarium. What this does is to help break down the ammonia content into nitrites, which are then broken down further into nitrites that are less toxic to your fish.

There have been debates on using two filters and over filtration as a result, and the effects it has on this bacteria. The beneficial bacteria grow in every area of your aquarium , yet the filter provides the ideal spot for it to grow. As water flows through this area, it makes contact with the bacteria. The issue being, if your filter was too powerful, then you will lose the contact time of water to the bacteria. While you are looking at two filters, you will need to decide on the kind of filter to use and the placement.

Two filters in one zone can create too much flow in one direction. When it comes to deciding on the size of your filter, you do need to take into consideration the kind of filter you will be using.

One of the most common filters in use for the majority of tank owners are outside filters. These make use of a pump to suck water through a tube from inside the tank.

Here, the water flows through a series of compartments and different types of media , before making its way back into the tank. When using this kind, a general rule to follow is the filter will have a flow rate of four to six times the volume of your tank. A gallon tank will have a GPH gallon per hour filter as an example. When looking at adding a second filter, you may think you can increase the size of your tank by double.

It will be easier than making calculations because most filters will state the size of tank they can accommodate. A second filter can be smaller; however, if you have a failure in your other pump, this redundancy will not be sufficient. You can take some media from your old filter and put it in your new filter. This will help speed up the colonization of bacteria. I have an aqueon 50 and I put a foam filter replacement from an aquaclear in the extra space to the left. I run more than one filter on most of my tanks just for the filter media and it also provides me with some place to get good used filter media if I need to set up a tank quickly.

Click to expand This leads me to my next question, for a filter that uses only one actual filter media, how do you prevent a new cycle when you replace the old filter media with a new one? My marineland has slots for two filters, I replaced them both at the same time as I thought I was a good thing to do, I now realise I probably shouldnt have done that but I think I may as well leave it now since the fish are doing good. But most filters don't have two slots for 30 gal or less , so how do you keep it from starting a new cycle?

Is the water that's in the tank good enough to keep the cycle alive? Just to answer the initial question, yes you can over filter. If the bacteria spreads itself to thin on the pads it makes the cycle less stable. Is it easy to do, not really. Anything that came out of your old filter will have bb on it. Placing any amount of bacteria-covered media will dramatically speed up the cycling process of the new filter.

The more, the better. I have been running two filters in my 29 for a couple of years now one for quarantine media , and I have never had any cycle-related issues.

Just make sure to keep them clean. I think that it it easier to get elevated nitrate levels when you have two filters full of poo instead of just one.

SoltarianKnight, what kind of gecko is that in your avatar? I had a leopard gecko when I was a kid. He was a neat pet. Beautiful animals. I have to respectfully disagree with soltarianknight on the possibility of a tank being able to be over filtered but you can easily under filter it. In my almost 50 years of keeping fish I have never encountered a single case of the filter media being so large that it became less affective, of course I have never hung 15 filters on a 55 gallon tank to test this theory.

Now this is not to say that water can not be too pure because it can. By doing regular water changes you are replacing most of minerals that the fish use but in some cases it is necessary to use additives to replace them, especially in saltwater tanks.

The bio-load of the tank and the available growing space for the beneficial bacteria determines the amount of beneficial bacteria that will grow and how much ammonia and nitrites that it can process. The same amount of bacteria is going to grow whether it is all in one filter or spread out over three or four of them and it will still be able to process the same bio-load.

It is not like you are deluding the bacteria but are just spreading it out and giving it more room for growth when needed. By running an over sized filter or more than one filter on a given tank you are providing a larger turn over rate of the total water volume than one filter sized for that tank can do. This is going to allow the filter s to process the water more times an hour which is going to lead to cleaner water but the bacteria colony is still only going to process the same mount of ammonia and nitrites but will allow the colony to adjust to a larger bio-load easier because it has more room to grown and places to attach than can be provided by the smaller or single filter.

Now having said that, it is possible to provide too much current in a tank for the fish to be comfortable. I am just saying that if you increase the amount of water that is turned over per hour and the amount of growing area for the bacteria your water will stay cleaner and the bacteria will be able to adjust easier to a larger bio-load if it increases.

Another point I would like to make is if all your beneficial bacteria is growing in one place you can easily affect the bacteria colony when cleaning.

If you are running two filters and only clean one of them during a water change then you only have the potential of killing off half of the beneficial bacteria if you over clean it or contaminate it, not all of it. It is true that if you use more than one filter on your fish tank, neither of those filters will perform as efficiently as it would if it were the only filter on the aquarium. This is expected, but is not a problem. Each filter is less efficient because of some of the restrictions placed on filtration systems by water volume and surface area.

Both water volume and surface area will influence the density of waste and of oxygen in the water, and this will directly impact the efficiency of the biological filter over all.

Because of the limitations on available oxygen in the water and the rate at which waste is produced and delivered to the filter, adding more filters will not increase the maximum population for your aquarium. This parallels the rationale behind not using bacteria boosters in an established fish tank. I almost always recommend using redundant filtration on your fish tank.