Filter questions

[yilduz]

I have a very large tank sitting around that has not been used for some time, and I was thinking of using it to create an aquatic environment, but I decided to do research before setting it up because there are a few specifics for which I want to use the tank and I want to make sure I do things correctly.

I did some Google searches for ways to set up a tank without using filters. I didn't really find any ways of doing it so I searched for fish forums and found this place. I read through your stickies and realized that there is a lot more to running a fish tank than I realized, but I'm still a bit curious to know if there is a way to run a fish tank without a filter.

From what I understand, the fish create ammonia with their waste, then bacteria converts it to nitrite, which is then converted to nitrate by another bacteria. After that, it's my understanding that algae and aquatic plants utilize the nitrate in the water. So... if I keep aquatic plants and a plecostomus or two, will that keep the nitrates in check? If so, what else needs to be filtered out of the water?

The reason I ask is because I don't want one of those filters that sucks the water up and pours it into the water again. One of my main desires for the tank is for it to be amphibious. I figured I would do this by putting a clay or ceramic plant pot (or two... or three... or some number) and filling it with soil. In them I figured I could grow grass or small plants that live near water. I'd like to keep amphibians in the tank with the fish, so I will absolutely do research to see what plays well together, but that's not my purpose of this thread here. The water level is not going to be near the top of the tank, so I don't want the splash of water falling several inches to the surface from a filter.

Any information or help would be greatly appreciated. I'm mainly asking about the filter, but if you have any suggestions or comments about the type of plant pot, plants, amphibians, fish, etc to use, or just suggestions or comments about how I want to set up the tank, I'd appreciate that as well.

Thank you.

 

[aakaakaak]

It sounds like you're attempting to create a terrarium of some sort. If you're planning on making sections with a water depth capable of supporting fish, but still not near the top of the tank I might suggest you get a sponge filter. They're small and don't need to hang anywhere near the lip of the tank. You normally just need an air line going down to the filter.

 

[OrangeCones]

You didn't mention how large this tank is, but anything larger than 20 gallons is going to need water movement to be healthy. You can accomplish that by a sponge filter as already mentioned, and it can be driven by an airpump or a submersible powerhead. (All of my tanks have the sponge/powerhead set-up).

If you are wanting a low-maintainance tank with potted plants submerged or partially submerged, look for the "Walstad Method" for some tips.

From what I understand, the fish create ammonia with their waste, then bacteria converts it to nitrite, which is then converted to nitrate by another bacteria. After that, it's my understanding that algae and aquatic plants utilize the nitrate in the water. So... if I keep aquatic plants and a plecostomus or two, will that keep the nitrates in check? If so, what else needs to be filtered out of the water?

Most aquatic plants (including algae), will use ammonia as the first choice of food for a source of nitrogen, nitrite 2nd, and nitrate last.

Although it is possible to have an aquarium with zero in all three nitrogen compounds, there is more than the nitrogen that must be regularly removed from a tank with fish.

If the tank is densely planted with a substrate of organic soil capped with sand or gravel, and the bioload low (plecos are a big bioload), Diana Walstad's methods can be used to keep water changes to 2 or 3 times per year. I've used the methods and enjoyed those tanks, but I prefer more high-light plants and like to re-do my aquascape. The soil substrate makes that more difficult.

 

[blue_ram]

A planted tank in itself can run without an external filter, but you will need at least a power head for water movement.

The biological filtration will occur inside the tank as the bacteria will colonize inside the tank and the water movement will circulate the nutrients and oxygen to the bacteria.

You will still have the problem of solid waste which will take years before the tank itself will be able to efficiently break down solid fish waste and dead organic matter.

Bottom line is run the tank for a year or so with filters before you attempt a filterless tank.

 

[yilduz]

Thank you both for all of the information. That is extremely helpful. I'm researching the Walstad Method, and sponge filters right now. I started looking for images of what I want to do, but found this video. YouTube - Newt and Frog Fish Tank Terrarium

This is extremely similar to what I want to do, but I want the water to be a little bit deeper, and the land area to be a little bit larger. Maybe I can do three levels because, to answer your question, I don't know the capacity of the tank, but it's about four feet long and fairly deep so it's not what I would call a small tank. I could have one level of land, a middle level of somewhat shallow water, and then a deeper section.

Edit: blue_ram responded after I already loaded the page so I didn't read his post until now. That will be some helpful information as well. I think I've given up the idea of filterless, at least until I get some more knowledge and experience running a tank like this.

 

[OrangeCones]

Maybe I can do three levels because, to answer your question, I don't know the capacity of the tank, but it's about four feet long and fairly deep so it's not what I would call a small tank.

If you measure your tank in inches, multiply the length x width x height, and divide by 231, it will give you the approximate gallons. When choosing equipment, it will be important to know the volume.

 

[brian1973]

There are also in tank filters that can be used, I recently had the same issue setting up a 40G breeder tank to house a young turtle, I have to keep the water level low and the filter I had purchased wouldn't work. The marineland Penguin hang on back filter I purchased for it struggled to pull the water in, which made the pump noisy not to mention the water fall effect dropping 8 inches was way to loud. I modified a whisper in tank filter that I had laying around, it has 2 small holes in the back of it for suction cups and a adjustable bar to hang it over the edge of a tank, I removed the bar and drilled the holes out to accommodate larger suction cups. Below is a link to the type I am using, but I will have to upgrade soon because the filter is way to small for my needs, so take that into consideration as well before you buy a filter, I am not sure how much of a difference amphibians make in the bioload so make sure you research that.
Product Catalog

 

[Thyra]

It sounds like you are talking about a "paludarium" Just Google that word and you will find all kinds of info including pictures.

 

[blue_ram]

For a paludarium, you can use a very small pond pump and let the water trickle down over a pebble stream.

eg..

66 GPH Mini Submersible Pump

Carve out a foam housing for a pump like that and run the outlet tube under the land area and up throught he soil .

 

[yilduz]

Thank you all for the information. After looking around the internet for paludariums, some of them are similar to what I want to do. A lot of them don't really have the land aspect and just use a lot of plants, but overall I think what I want to do would be called a paludarium.

I like the idea of the river and I even saw it in a couple of examples I found. It is a very nice touch and something I intend to include.

I've recently learned that I have a lot of time to research and plan my project, though. I assumed the tank was here with me in Nevada, but it's actually in Wisconsin and there is no saying when I'll have it in my possession. I'll keep researching and looking for ideas until I get it, though.