About Filters, Different Types, Etc

[Rediahs]

The main thing I haven't been able to figure out in this hobby is filters. Maybe it's just me, never having owned a proper tank (only small betta tanks without filters) but I don't understand filters.

There's so many different types... I don't understand how they work, what they do, all I know is that you have different filter media and that's where the bacteria lives and that's why you need to do cycling... but the filter itself I can't figure it out.

I am trying to plan a 29 gallon aquarium... I've been looking through classifieds trying to buy from people in my area for cheap because I'm on a tight budget. However.... if it doesn't come with a filter, I'm at a loss as to what I should get.

I don't understand all this stuff, power heads, power filter, canister filter, hob filter... I heard someone say canisters are bad?

Can someone explain about filters, or show me a good resource to understand filters? I'm kind of mechanically challenged and I want to understand what I'm trying to achieve before buying a filter. I also want to know how much money I need to be willing to spend to get a decent filter. I have been looking but I can't figure that out.

 

[loachman]

The main thing I haven't been able to figure out in this hobby is filters. Maybe it's just me, never having owned a proper tank (only small betta tanks without filters) but I don't understand filters.

There's so many different types... I don't understand how they work, what they do, all I know is that you have different filter media and that's where the bacteria lives and that's why you need to do cycling... but the filter itself I can't figure it out.

I am trying to plan a 29 gallon aquarium... I've been looking through classifieds trying to buy from people in my area for cheap because I'm on a tight budget. However.... if it doesn't come with a filter, I'm at a loss as to what I should get.

I don't understand all this stuff, power heads, power filter, canister filter, hob filter... I heard someone say canisters are bad?

Can someone explain about filters, or show me a good resource to understand filters? I'm kind of mechanically challenged and I want to understand what I'm trying to achieve before buying a filter. I also want to know how much money I need to be willing to spend to get a decent filter. I have been looking but I can't figure that out.

Here are the main 4 types of filters.

Sponge filter - uses a sponge with a vertical tube down the middle with an airstone. The bubbles rise up the tube and pull water through the sponge with it. They're good for small tanks, fry, and fish that do not do well with much flow. The sponge acts as a biological and mechanical filter. Inexpensive filters (~$10 + $10 airpump).

HOB - (hang on back). Uses a pump to pull water from the tank and through a filter. Typically do biological and mechanical filtration, but can also do chemical filtration with the right media in the filter pack. They're the most common on small to medium tanks (10 gal+). They tend to "eat where they poop" as the intake is usually right under the outlet so they're not the most efficient at cleaning the entire tank. Therefore, they tend to not work well in large tanks. Inexpensive filters (~$15+)

Undergravel - They use the gravel as the biological and mechanical filtration, chemical media can be added to some models. They have a huge surface area as the entire gravel bed is used for bacterial growth. Older technology that requires a serious gravel clean every couple months as the filter pulls detritus into the gravel. Can't be used with sand substrates. I'd advise against them.

Canister - Best for larger tanks. They have an external canister that is filled with filter media. A pump pulls water through the filter and discharges it back to tank. Can do biological, chemical and mechanical filtration and are probably the most efficient filters (place the inlet and outlet on opposite sides of the tank). Can cause flooding if they leak. Most expensive of the filters.

 

[hollanda88]

Here are the main 4 types of filters.

Sponge filter - uses a sponge with a vertical tube down the middle with an airstone. The bubbles rise up the tube and pull water through the sponge with it. They're good for small tanks, fry, and fish that do not do well with much flow. The sponge acts as a biological and mechanical filter. Inexpensive filters (~$10 + $10 airpump).

HOB - (hang on back). Uses a pump to pull water from the tank and through a filter. Typically do biological and mechanical filtration, but can also do chemical filtration with the right media in the filter pack. They're the most common on small to medium tanks (10 gal+). They tend to "eat where they poop" as the intake is usually right under the outlet so they're not the most efficient at cleaning the entire tank. Therefore, they tend to not work well in large tanks. Inexpensive filters (~$15+) can contain carbon to remove medicines if used and can be customised to how you want it (differetn sized pads, bioballs, carbon)

Undergravel - They use the gravel as the biological and mechanical filtration, chemical media can be added to some models. They have a huge surface area as the entire gravel bed is used for bacterial growth. Older technology that requires a serious gravel clean every couple months as the filter pulls detritus into the gravel. Can't be used with sand substrates. I'd advise against them. Can't have any other types of filtration i.e. can't have carbon in it

Canister - Best for larger tanks. They have an external canister that is filled with filter media. A pump pulls water through the filter and discharges it back to tank. Can do biological, chemical and mechanical filtration and are probably the most efficient filters (place the inlet and outlet on opposite sides of the tank). Can cause flooding if they leak. Most expensive of the filters. can contain carbon and other things and are common on larger tanks

 

[loachman]

Filters do 3 types of filtration.

Biological - Often referred to as the nitrogen cycle, bacterial on/in the filter convert ammonia to nitrite to nitrate. Ammonia is produced by fish and other organisms as waste. Ammonia and nitrite are highly toxic, so the biological filtration makes the water safe.

Chemical - removes chemicals from the water. Typically this is done with activated carbon that acts as an adsorbent media to capture unwanted chemicals

Mechanical - removes physical things from the water column much like a standard "filter" you'd use in your kitchen or house. It captures solid waste, uneaten food, etc.

Undergravel - They use the gravel as the biological and mechanical filtration, chemical media can be added to some models. They have a huge surface area as the entire gravel bed is used for bacterial growth. Older technology that requires a serious gravel clean every couple months as the filter pulls detritus into the gravel. Can't be used with sand substrates. I'd advise against them. Can't have any other types of filtration i.e. can't have carbon in it

Some can incorporate carbon or other chemical media on the outlet near the pump. Not all models do though.

 

[Rediahs]

Sponge filter - uses a sponge with a vertical tube down the middle with an airstone. The bubbles rise up the tube and pull water through the sponge with it. They're good for small tanks, fry, and fish that do not do well with much flow. The sponge acts as a biological and mechanical filter. Inexpensive filters (~$10 + $10 airpump).

I don't think I understand this.... okay so does the filter require power (like needs to be plugged in)? Or is there just an airpump going through the middle? Kind of confusing...

 

[hollanda88]

Sponge filter - uses a sponge with a vertical tube down the middle with an airstone. The bubbles rise up the tube and pull water through the sponge with it. They're good for small tanks, fry, and fish that do not do well with much flow. The sponge acts as a biological and mechanical filter. Inexpensive filters (~$10 + $10 airpump).

I don't think I understand this.... okay so does the filter require power (like needs to be plugged in)? Or is there just an airpump going through the middle? Kind of confusing...

The airpump requires power,

 

[fatheadminnow]

Very nice write-ups!

There is also one more type of filter that was not mentioned, this filer is called a sump, wet/dry filter or a trickle filter.

This is where there is an over-flow, where the water flows over the over-flow and through the bulk head.

Then this water flow can travel through various methods of filtration.

Usually, the water is spread out over a large surface with holes in it, then the water will flow through the holes.

Then usually the water flows over a huge sponge/mechanical filtration.

Than the water flows over a good biological filtration system, like bio-balls.

This all happens in a vertical column.

Next, the water flows through a body of water, usually 10 gallons, also known as the sump.

This is where heaters are usually added, and meds as well. Along with other things.

If you wanted to clone bacteria for mature media to sell, this is where you would through sponges and what not.

Finally the water flows to a pump, where it is then returned back to the tank.

With water constantly flowing into the tank, the water level is always going to be rising and falling back over the over-flow, and back into the sump.

This type of filtration is usually for larger tanks/ponds.

-FHM

 

[Rediahs]

Sponge filter - uses a sponge with a vertical tube down the middle with an airstone. The bubbles rise up the tube and pull water through the sponge with it. They're good for small tanks, fry, and fish that do not do well with much flow. The sponge acts as a biological and mechanical filter. Inexpensive filters (~$10 + $10 airpump).

I don't think I understand this.... okay so does the filter require power (like needs to be plugged in)? Or is there just an airpump going through the middle? Kind of confusing...

The airpump requires power,

Only the airpump? So if I understand it sorta works like a vacuum in a way... pulling stuff through because the air comes through?

I don't really have a clear picture of it in my head but it sounds cool...

 

[waterdrop]

Sponge filter - uses a sponge with a vertical tube down the middle with an airstone. The bubbles rise up the tube and pull water through the sponge with it. They're good for small tanks, fry, and fish that do not do well with much flow. The sponge acts as a biological and mechanical filter. Inexpensive filters (~$10 + $10 airpump).

I don't think I understand this.... okay so does the filter require power (like needs to be plugged in)? Or is there just an airpump going through the middle? Kind of confusing...

The airpump requires power,

Only the airpump? So if I understand it sorta works like a vacuum in a way... pulling stuff through because the air comes through?

I don't really have a clear picture of it in my head but it sounds cool...

LOL, enjoying this ... because when I was growing up, virtually the only affordable filters were *all* run by airpumps producing bubbles through them. Now "powered" filters have become so common that its become difficult to describe the simple airpump filters to people... (sorry, you can perhaps picture how this would have to bring a smile to the old guys...)

Let's see I'll give a crack at it (since I'm known for being long-winded ) and I'll probably fail anyway, lol... So you understand airpumps, right? The common ones are little buzzy vibrating boxes that plug into wall power and push air through a little thin usually clear tube and are commonly used nowadays for airstones and bubble wands and such, right? OK, so you have to get in your head that this little push of air actually has a little power to push things, not much, but a little.

If you take the thin airtube and run it down low in the fish tank, you can do stuff with it depending on what sort of plastic thing you connect it to. Let's say you connect it to the bottom of a very simple clear plastic stiff tube, just a little wider than the airhose itself. Lets say we hold that tube in a vertical position. The air will come out of the flexible air tube at the bottom of the stiff tube and it won't fill the stiff tube with air, instead the air will form bubbles. Let's say the bubbles are forming very slowly so we can see what's going on. A single bubble forms at the bottom of the stiff clear plastic tube and we can see it. It rises to the top of the stiff tube. As it rises, guess what its doing? Its *lifting* the water on top of it in the tube! Its doing a little bit of work! OK, so now picture several of these bubbles rising, each one filling the width of the stiff tube. Between each air bubble there will be a bit of water, about the same size as the big air bubble lets say. Each of those bits of water is pushed up and out of the top of the stiff tube and back into the aquarium. Got that part? (And the water its lifting has got to come from somewhere, so its creating some suction, its pulling some water from its surroundings.)

Next, lets picture that we drill some small holes in the sides of the stiff clear plastic tube, just here and there, a few of them and they are fairly small but not tiny. Our tube is still held vertical. So now when the bubble goes up (it will still be easiest for it to go up, it won't go out the side holes) it will be able to easily get more water to push up from these side holes, make sense? Good! Now, lets picture that we surround our tube (is it a holy tube now? ) with a plastic box that's filled with that white pillow-stuffing stuff we call polyfloss, do you know that stuff? Let's say its a solid box but up at the top we put a few small holes. Well now you can picture the water coming into the box, having to pass through the polyfloss and then into the holes on our central tube and then "whoop" it gets carried up and out again by a bubble and if that water had any little debris particals in it, they might have been trapped by that polyfloss...

Oh my gosh, I'd better quick put a picture in, ok here... Simple bubble box filter!
(otherwise those webwise fellows on here will have a utube video and beat me to it, lol)
Note that in that picture our central tube doesn't have holes (hasn't been going to church I guess ) but that's just a variation where its just pulling water from the bottom, near where the air hose is adding air.

Lets also mention that instead of a box with polyfloss, you could just poke a hole through the middle of a large square of sponge and push our "holy tube" down the middle... then the sponge and air-driven-holy-tube would together form their own simple filtration system. Thats what loachman is talking about.

oooh, getting fancy.. yet another picture... Simple homemade sponge filter!

(if anybody actually reads this, let me know so I can be amazed and have a laugh)
~~waterdrop~~

 

[loachman]

Yeah, what "~~waterdrop~~" said. Basically as the bubbles rise through the tank, they create a gentle upward flow of water. If you put the air hose in a solid tube, water is drawn in the bottom and out the top as the air bubbles rise. Because the bottom of the plastic tube is stuffed into a sponge, the upward flow is supplied by water that passes through the sponge.

 

[OldMan47]

A very nice writeup WD. Yes you can be amazed, I did read it.
One type of filter that is becoming quite common is an internal filter. They work much like a HOB but are designed to be hung on the inside of the tank instead of the outside. A lot of the Whisper filters with model types that end in an "i" are pretty much cartridge style HOB filters that are placed inside the tank. They still draw water from the tank, make it pass through a filter cartridge using a pump and return the water to the tank through an overflow. They are dirt cheap to buy and average quieter than a HOB because the pumping parts are in the water and the water acts like a muffler for the mechanical noises.

 

[backtotropical]

A very nice writeup WD. Yes you can be amazed, I did read it.

I skipped right over it to the next post.........

Only kidding WD!

 

[mixmaster jay]

just get an external canister filter you will only need a small one for your tank

have a look at this link to see what i mean mate

http/cgi.ebay.co.uk/FLUVAL-105-EXTERNAL-...8QQcmdZViewItem

 

[Rediahs]

Okay guys, thank you so much I've read all this and it did help... but I have already bought a tank today, which came with a HOB filter and I am trying to understand it. I made a new topic requesting some help understanding the filter I bought.... it's here: http/www.fishforums.net/index.php?showtopic=286647

 

[waterdrop]

Yes, think I saw your other post about the new filter Chrissi. Kind of frustrating, as you gradually understand the different filter media and volume issues, to see what the manufacturers put in there.

~~waterdrop~~