Hi all. I seem to be nothing but questions on this board ever. I'm getting more and more into the aquarium hobby. I'm up to 6 tanks. (Help, I'm drowning! XD) I've taken care of some sick fish, and getting to be a little more knowledgeable, but there's one subject that I am clueless on.
Everything I own is some kind of charcoal filter, which doesn't seem to be the filter media of choice around here? I've seen some under gravel filters as well online, but have never seen one at a store. If someone could give me a quick rundown on different types of filters and their pros and cons, I'd be forever grateful.
I've rigged up a couple of filter baffles for the filters I do have, since the water currents were blowing my babies all over the place, but they still have a little trouble around the filter intakes.
I've also got one very small filter that's driven by an air pump. If someone could explain how this thing works, I'd appreciate it.
Oh! And also I've seen people recommend not changing filter media for a long time, and just rinsing your old stuff out in dechlorinated water from time to time. My filter media falls apart if I try!
Last edited by KappaTheImp; 07-30-2012 at 08:19 AM.
Reason: Thought of another question.
There are three kinds of filtration: biological, mechanical and chemical.
Biological filtration is achieved through the use of beneficial bacteria. The bacteria eat up ammonia and convert it into nitrite, it is then eaten by more bacteria of a different species and converted into nitrate. In low doses ammonia and nitrite can be deadly to many species of fish whereas nitrate in the same amount is next to harmless. Prolonged exposure to high nitrate can cause health problems in fish and algae blooms so we do water changes to remove this chemical from our tanks.
Biological filters usually contain a sponge to allow benefical bacteria to colonize, others use "media bags" containing bio balls, ceramic balls or other such material with lots of surface area. The more surface area the media has the more beneifical bacteria it contains and thus the more effective your filtration. The media cannot simply be dumped in a tank though as the BB needs good water flow and oxygen to survive. Pure biological filters are known as sponge filters and utilize an air pump; I prefer sponge filters as they have next to no flow and are very easy to control.
The media housing the BB can be rinsed in old tank water every now and then to remove crud but it musn't be cleaned too thoroughly nor dunked in chlorinated water as this will kill the bacteria thus restarting the filters cycling (have you heard the phrase: "you aren't cycling the tank, you're cycling the filter"?). It is normal for established and well-cycled sponges to look very dirty.
Mechanical filtration is achieved through the use of a powerhead or suction system to take in larger particles of muck and debris. It simply helps to do the job of an aquarium syphon but on a more consistant basis. Mechanical filters are good for biological filtration (if they house a sponge) as it sucks in water, pushes it through the filter media and back into the tank thus offering both mechanical and biological filtration. Some contain carbon/charcoal inserts.
Examples of mechanical filters are powerheads, canisters and hang on back (HOB) filters. They sometimes come with adjustable flows but are generally too powerful and create too much surface movement for bettas to live comfortably. Most mechanical filters can be baffled to be suitable for bettas but sometimes it is exceptionally frustrating.
Chemical filtration is achieved through the use of charcoal/carbon pads. These pads are usually put into powerheads, canister and HOB filters, water is forced over them and the carbon does its job by taking out impurities and medications from the water (except aquarium salt). These need to be replaced once every few weeks as they eventually lose effectiveness. Some filters contain sponges that are infused with carbon.
Carbon is known to be deadly to shrimp and should not be used in their tanks (I can't find my source for this piece of information, I know copper is deadly but read somewhere carbon is too, I apologize if this information is incorrect), it should also not be used in hospital tanks due to it sucking out all the medication one may use.
Another thing I've read about carbon -- please be aware that I'm not 100% certain as to the legitimacy of this -- is that it also takes nutrients out of the water which can lead to plants losing their luster and fish getting conditions such as hole in the head syndrome due to lack of nutrients. Again, I don't know the legitimacy of this.
The types of filters you can buy are: Hang on Back (HOB, usually containing all three filtration types), under gravel (I think this is just mechanical, powered by an air pump), sponge filters (biological filtration powered by an air pump), canisters and powerheads (can contain all three) and moving bed filters (must be home made, powered by an air pump and offers biological filtration, can be adapted to include chemical I suppose). I may have forgotten something.
HOB filters seem to be common for betta tanks and can be baffled through the use of a plastic water bottle or sponges attached with elastic bands, the intake tube can be baffled by wrapping a sponge (or cutting a hole in a sponge to fit the intake) around the intake opening to stop fins getting stuck.
Canisters and powerheads can be difficult to baffle but it is possible. When I attempted to baffle mine Kaze kept jumping into the baffle so I gave up. Some canisters come with a water skimmer that can be pointed towards the back of the tank to baffle it, there will be a small area of rapid water movement around the back of the filter but everywhere else should be fine.
Sponge filters cannot be baffled as they need not be. They create a steady stream of bubbles that are released at the top and this stream can be controlled through the use of an air control valve.
I've never used under gravel filters so I'm not sure what to say about them.
This is all I know on filters... I'm not sure if I've forgotten something but I hope it helps, heh. If any of the above information is incorrect please let me know, I'm still learning as well.
Last edited by SpookyTooth; 07-30-2012 at 08:56 AM.
Reason: More info!
Thank you for the response. I've been looking up sponge filters and they seem like the popular choice for bettas. What will they do to the surface of the water? If they're air driven, it seems like it would disturb the surface nearly as badly as my HOB filters.
And thanks for the info on carbon... I hadn't heard that. Explains why I keep losing ghost shrimp.
Agh, I think I mixed stuff up - I've read somewhere that you shouldn't use carbon in shrimp tanks. I know copper is deadly to them but can't find my source of info regarding carbon - I'm ever so sorry! Heh.
Sponge filters can create a lot of water disturbance if you have the air flow at maximum, but most air pumps come with a flow valve to give you complete control. My sponge filter is set to flow at such a slow pace that it only releases the odd bubble. It still filters very effectively. If you buy a sponge filter/air pump I'd also suggest getting a non-return valve to stop water flowing backwards into the air pump.