Biological Filter Heart Of A Tank?

[Sora]

Hello all, I was kind of hearing something and the proffessor said that "biological filters are the heart of tanks", does this mean I would need to get a biological filter? And what biological filters are there? Because I heard something like using some sort of bioballs?? I wasnt to sure about this, and wasnt to sure if it was for freshwater aquariums as well.

I've also heard when doing the fishless cycle that your bui;ding your biological filter, so in that way you dont need to worry. Thats why im kind of unsure.....

Any suggestion/thoughts/help will be brilliant.

 

[Honeythorn]

Well yes they kind of are. The bacteria in the filter media consume the waste products of the fish and convert them to less harmful products, which YOU then remove with weekly water changes. Basically the filter keeps the levels steady and provides a more stable water chemistry for the fish. The filter you get depends on your tank size and how many fish you would like to keep. If you're having just a male betta for example, then you could just get a simple sponge filter.

When you fishless cycle, you are building up the colony of useful bacteria in your filter media by adding pure ammonia instead of having actual fish to produce waste. When the cycle is complete, you add fish slowly to allow the newly formed colony to grow more and adjust to the extra waste.

 

[OldMan47]

That's a good answer Honeythorn. The essence of a bological filter is anything that has a constant flow of oxygenated water over it. It will eventually develop a coating of biologically active bacteria to help convert ammonia. The larger the surface area, the better biofilter it will be. It can be sponges, "noodles", ceramics, pot scrubbers, or anything alse that is inert and has a large surface area.

 

[waterdrop]

Yes, agreed.. excellent answers above.

(read this when you get bored )

And from another angle: The term "biological filter" or "biofilter" for short, refers to one of the three main functions of the physical filter you will buy and use. One function, that of "mechanical filtration" is the one that most people are familiar with, that of trapping particles of debris and waste in the mesh of the sponges or floss in the filter. Another function, that of "chemical filtration" is a special case that we don't usually need under normal circumstances - a common example of that is the use of carbon (aka charcoal, aka activated carbon) which is used to clear medications that have been used or to remove yellow tannins from bogwood or unusual organic smells. Carbon only lasts about 3 days and then can be removed.

The third and, as we've all agreed, most important filter function is that of the biofilter as described by honeythorn and oldman47 up above. I know I'm repeating the pinned articles you've probably read at the top of our forum but its so fascinating: Unlike the carbon dioxide we breathe out, the fish give off ammonia(NH3) when they respire with their gills. Their waste is also broken down into ammonia. The excess food they don't eat and the dead pieces of plants also both break down into ammonia.

Ammonia is bad for fish because is burns their gills. The burning is serious and can cause permanent damage. Amounts even smaller than our test kits can measure cause irritation.

The first of the two good bacteria species that grow in the biofilms on our filter media are the ammonia oxidizers (sometimes we call them "A-bacs" or "AOBs") and they eat ammonia and convert it to nitrite (NO2). A mature A-bac colony is very, very fast at converting ammonia into nitrite.

Nitrites (NO2) are also bad for fish. Nitrite attaches to the hemoglobin molecule in the fishes blood as if it were oxygen. When it does that, it keeps oxygen from being there and the fish begins to suffocate. Even small amounts of this can cause permanent damage.

The second of the two good bacteria, the "nitrite oxidizers" (aka "N-bacs" or "NOBs") will eat nitrite (NO2) and convert it to nitrate (NO3), which is also not a great thing to have in our tanks but it is much, much less toxic to the fish than either the ammonia or the nitrite. Many aquarists like to try and keep nitrates at 40ppm or below as good practice but fish have been found to tolerate quite high amounts, like 100ppm without death. Nitrates get removed by water changes.

Anyway, that's the somewhat longer version that contains what a "biofilter" is, if it was clear enough to follow.

~~waterdrop~~

 

[Corleone]

Very through answers, but you do mention fishless cycling, which isn't covered in quite so much detail. There's a very good thread on it stickied in this section.

A basic rundown of fishless cycling, some other means of introducing ammonia into the tank is used to promote the growth of your biofilter instead of fish waste. This can be bottled household ammonia, fish food, cocktail shrimp, or even the tank owner's own urine in some cases. There's been threads about why pee may or may not be a good idea, and it's definitely the least appealing method to most people. Bottled ammonia is the most controllable and easiest to monitor, but appropriate ammonia (dos and donts are covered in the article I linked) isn't easy to come by for some people.

As waterdrop covered, the process of growing a biofilter (which is what's usually referred to as "the cycle" in the hobby) is dangerous to fish because ammonia and nitrite are still present in appreciable amounts. The traditional solution is to use a light stocking of very hardy fish that have a higher chance of surviving this, then slowly stocking from there to let the biofilter grow with the fish. The downsides are varied - even hardy fish will be put in danger in the process, and suitable fish for the cycle process may not fit into stocking plans for the tank, leaving you with fish that might be hard to get rid of.

Fishless cycling removes the chance of killing fish entirely by simulating the waste production of a full stock of fish without actually risking fish. It's a lot less work for the fish keeper, who would otherwise have to constantly change water to protect their fish and don't have to worry about rehoming a stock of unwanted fish at the end of the process, and much kinder on the fish, who are spared one of the leading causes of death for pet fish.

 

[Sora]

Thank you so much everyone, I know understand about biological filters thanks once again!

 

[jnms]

Really good info.

I have a Fluval 305 filter, it came with carbon as one of the media - does carbon prevent or slow the build up of biological filtering at all?

 

[Miss Wiggle]

i like the 'heart of the tank' expression, think i'm gonna rob that!

Have to say Sora I really applaud you for all the time and research you're putting into this before you've even got your tank, think you're gonna turn out to be a brilliant fishkeeper

Refreshing to see someone going about it this way rather than just diving in getting a tank and fish and then asking questions.

 

[aaronnorth]

carbon takes out metals in the tank, it doesnt affect the nitrogen cycle. It is highly porous and good for biological filtration. After a few days to weeks, it can start to leak if it becomes to saturated.

 

[jnms]

carbon takes out metals in the tank, it doesnt affect the nitrogen cycle. It is highly porous and good for biological filtration. After a few days to weeks, it can start to leak if it becomes to saturated.

Leak Bacteria? So is carbon not very good for a fishless cycle?

 

[Miss Wiggle]

there's a lot of debate over weather carbon actually does leech back into the tank.

he doesn't mean it leech's bacteria though.

There's a theory that once carbon has become saturated with whatever it has absorbed (i.e. medications, heavy metals etc) it will hold it for a few days and then it'll all start to leak back out into the tank.

This is widely contested though.

IMO carbon should only be used to remove unwanted meds or any toxins from the water, so when you need to remove something you add carbon, then 24hrs later you remove it and through it away.

If you leave it in any longer it's not doing the job it's intended for, while it will act as bio media it won't do it as well as media made specifically for that job so if you want to keep it for that then you may as well just save a few quid and buy a sponge

 

[K-Holed]

There is little point in using carbon during your fishless cycle. Carbon is a chemical filteration and is most useful for removing medications from water and such. The activated charcoal only has a finite capacity and once this has been reached, it will start to leach any heavy metals and such, back into the aquarium. The life of activated charcoal has been reported to be extended by boiling and reusing.

As for the filter being the heart of the aquarium ... maybe more the liver and kidneys ... but that doesn't sound half as poetic =)

//James

 

[Sora]

lol, im going to re-read the fishless cycle and the different medias that can be used for the filters. But thanks once again everyone... this is the first community thats helped me this much

P.S - I did have fishes a long long while ago, but because of my insufficent knowledge it kinda went down hill.... for instances I had gravel and no gravel vac or anything to remove the the fish waste and food that was remaining. So yeh, i went through a wierd time. (But I was young then, about 6 years ago, and since then I havent gotten back into it.... well until now when my family gave me $$ for a present doing well in college)
So im planning to learn from my mistakes and insted of jumping in the boat, going to research and research and research until October (when we get new funiture so I can then get my fish tank)

 

[Corleone]

Great plan A lot of people recover from bad starts (usually a result of doing what the pet store suggests - THAT'S a whole discussion in itself), but a good first experience is invaluable, and might the difference between a month long diversion and a lifetime obsession. A bad cycle experience can be disheartening, and a lot of people lose hope and give up, many without ever finding better help than the pet store offered.

Now until October's plenty of time, too. There's lots of resources on this site, anything in or linked from the stickied threads in this forum is worth a read, and you can go through the species index and get some general ideas of what you want. Become a fixture around your local fish stores, too - the first thing I did while I did my fishless cycle was get an idea of when the new shipments come in at all the stores, so I can always get in and get a look at interesting arrivals before they get snatched up, or special orders before they're picked up. You'd be amazed the difference in selection at some of the really popular stores from delivery time just to the end of the day.

 

[Miss Wiggle]

Become a fixture around your local fish stores, too - the first thing I did while I did my fishless cycle was get an idea of when the new shipments come in at all the stores, so I can always get in and get a look at interesting arrivals before they get snatched up, or special orders before they're picked up. You'd be amazed the difference in selection at some of the really popular stores from delivery time just to the end of the day.

definately, particularly with plants i think this is useful, we know a few local stores that stock tropica plants but don't have the facilities to look after them properly, if you get them on the day of arrival though they're usually good!