Can Cichlids Live Without A Filter? (What You Need To Know)


Filter-less tanks are becoming more popular just like taking care of Cichlids are. In this post, we’ll address the question of whether these two can be combined. Is a filter really necessary for a Cichlid tank?

It’s very hard for Cichlids to live without a filter because their survival depends on how clean, balanced (cycled), and oxygenized their water is. These are provided easily by a powerful filter. If you want a filterless aquarium, you have to have a very small bioload and a high amount of natural biological filtration.

A filterless tank won’t be possible for the usual Cichlids that grow up to 5, 8, or 10 inches long unless you want to change 50 to 70% of the water daily. That’s a huge amount of work nobody would want to put up with.

Why Can’t Cichlids Live Without A Filter?

There are several reasons why Cichlids can’t live without a filter.

Reason #1: Most Cichlids live in groups

To maintain an aquarium without a filter, your bioload must be very small. There are a few types of Cichlids that can live alone like an Oscar, but most Cichlids like to live in groups. However, even Oscars still grow very big and thus, would need lots of filtration.

We talked about stocking Cichlids in our previous post “Are Sponge Filters Good For Cichlids?”. Oftentimes, you can’t keep only a few of the more aggressive ones. Therefore, more fish means more waste, and more waste means the need for higher filtration capacity. Moreover, you’ll need more oxygenation, or else you’ll be left with Cichlids gasping for air just like we described in our post “Here’s Why Cichlids Stay At The Top Of The Tank”.

Reason #2: Cichlids create a lot of waste

Even with a few Cichlids, you’ll have trouble keeping water clean without a filter because they have very healthy appetites. This translates to, again, creating a lot of waste inside the tank. And since they’re sensitive about water quality, then a high amount of filtration is necessary to get rid of all that waste.

Reason #3: Plants cannot substitute the amount of filtration a Cichlid needs

Nano tanks or filter-less tanks need an excessive amount of plants to make up for the lack of artificial filtration and oxygenation, both of which are highly important in a Cichlid setup.

Can Cichlids Live Without A Filter
Can Cichlids Live Without A Filter

The problem with plants is that you can’t have too much of them in an average Cichlid tank because these fish dig them up. While there are some plants they won’t bother, such as what we listed in our post “This is Why Cichlids Destroy Aquarium Plants”, the usual Cichlids are not the type of fish that would live successfully in heavily planted tanks.

Reason #4: Cichlids grow big

The average size of a mature Cichlid is 6 to 8 inches. The bigger the fish, the more they eat, the more oxygen they need. That’s a lot of ammonia and nitrites to be dealing with without a filter.

But what if we only have a couple of tiny Cichlids? Let’s explore the possibility of putting them in a filterless tank.

The Filterless Cichlid Tank

The Walstad Method by Diana Walstad has become famous for creating the now popular nano tanks which are filterless and heavily planted. It recreates a balanced, natural environment for fish as long as the bioload is very light.

The method uses lots of plants and healthy soil to oxygenize the water and filter out any waste the fish will produce. The plants absorb waste and toxins while the soil provides enough nutrition and CO2 (carbon dioxide) to keep the plants healthy. The soil also contains trace metals that will keep the pH high enough and the water healthy. Ample lighting (low to medium light) completes the setup.

Certain small fish, such as Bettas, Dwarf Rainbowfish, Japanese Rice Fish, and Killifish have been successfully kept in these setups. Therefore, some Dwarf Cichlids, such as Apistos (Apistogramma) can qualify to live in a filterless tank as long as all their needs are met. They can be small enough not to be as demanding as their average 8-inch cousins.

The Walstad Method is a low-tech setup that doesn’t use any gadgets, so an Apisto tank would need a thick layer of healthy soil underneath the sand substrate, lots of different plants, and a full-spectrum LED light set if sunlight is not possible.

Can Cichlids Live Without A Filter-Explore It Here
Can Cichlids Live Without A Filter-Explore It Here

On the other hand, a high-tech setup may use a CO2 tank, a bubbler, and weekly 50% water changes to keep the tank clean. If your place doesn’t have enough ambient heating, you will need a heater, too. Plant growth will be rapid, and there’s always the danger of an algae bloom.

Both these methods are plant-centric, meaning plant health comes first before the fish. They require research on the right kind of plants that respond well to these conditions.

How Long Can Cichlids Go Without A Filter?

But what if you had a regular Cichlid tank and there was an emergency? Extenuating circumstances such as a power outage might make your filter unusable.

The length of time a group of Cichlids can survive without a filter depends on how much bioload the system takes before it crashes. To avoid crashing, there should not be an abrupt change in temperature, nitrifying bacteria content (ammonia, nitrates), pH, and dGH.

We list below some tips that may help you keep your Cichlids alive and healthy  during these emergencies.

How To Sustain Cichlids If Your Filter Stops Working

We’ve had fish keeper friends who suffered a storm in their area or had a broken filter and couldn’t replace it right away. If this happens to you, there are steps you can take to ensure your Cichlids’ survival.

During these emergencies, what’s important is to:

  • Keep the water clean enough, free of ammonia and nitrites
  • Provide enough oxygenation for the Cichlids to breathe properly
  • Prevent abrupt changes in temperature, pH, and dGH.

In these situations, the lack of filtration should be temporary until the situation can be solved.

Tip #1: If you’re aware of an oncoming power outage, change the water beforehand and try not to feed your fish too much. The point is to maintain clean water by minimizing the amount of waste the Cichlids will produce during the outage. If the outage is only a few hours, you can opt not to feed your fish half a day before.

Can Cichlids Live Without A Filter- Avoid Bioload
Can Cichlids Live Without A Filter- Avoid Bioload

If you’re using a sump and the power outage is taking days, take the Cichlid filter media (the bio media) and put it in a gravel sack. Then place the sack directly into the tank.

The first aid for a sudden ammonia spike is to add some water conditioner. As always, be very careful with the dosing.

Tip #2: Temperature can be maintained by taking some water out and carefully adding hot water every few hours to the tank. A larger aquarium will not suffer heat loss too much, but you can supplement this by insulating your tank with towels, an insulation pad, or blankets.

Tip #3: Try using battery-operated bubblers or air pumps to maintain the amount of oxygen in the water. You can place your air stone underneath the gravel sack with the Cichlid filter media for more effective filtration. If you don’t have battery-operated air pumps, you have to stir the water every half hour to create enough surface agitation for oxygenation.

An overstocked tank will have more problems in a prolonged outage so be extra diligent if you’ve got lots of fish. Having a backup generator is practical if your area is prone to such emergencies.

If you are interested in learning more about your fish behavior, check out the links below:

Wishing Your Cichlids The Best!

Your filter might not be available by choice or circumstance, but make sure that all functions are kept going (biological filtration and oxygenation). These are what your Cichlids depend on to live, so stay calm and make the right choices.

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