An understanding of filtration

[Toker95]

Howdy folks,

I'm relatievely new to the aquarium world, I have a 30gl tank which is now being upgraded to a 72gl bf tank. In researching what filter/s I'll be using, all of the larger designs for a tank this size appear to give options for filter media.

I've read a good bit here and around the web regarding filtration and its importance. Thats the easy part, I've pretty much decided on the Emperor 400 for now, and might upgrade/double it in time as needs warrant.

However, I read an article recently that explained how bad activated carbon is for a tank. Bad in the sense that it cleans EVERYTHING out of the water, not just the ammonia and solids. I.e. it removes both the beneficial and harmful bacteria from the water itself. I'm trying to understand this... as I don't see alot of options for either canister or HOB filters that doesn't include activated carbon. So as I've pondered the idea, I came up with an explanation....

Most experts seem to push the concept of Bio-Filters, I'm guessing that the bio-filter, housing beneficial bacteria cleans the water naturally, and the rest of the filter/carbon finishes/polishes the water. With a Bio-filter, there isn't as much need for the beneficial bacteria in the water itself, as its still growing on the wheel, and on surfaces inside the tank.

Would this be a safe assumption? Or is there a better way of explaining things...

 

[Jchillin]

The idea of filtering everything "harmful" out of your water led to the current "3 stage" filtration systems. Activated carbon/charcoal does remove a lot of hard minerals. It isn't necessary to use if you don't have this type of water problem. Plus, the charcoal/carbon becomes de-activated after @ 1 month.

The charcoal/carbon can be replaced by either additional bio media and/or other beneficial media (peat for example). The foam/sponge removes solid waste and polishes the water.

To answer your last question, with enough bio-media in your filter, bacteria will continue to enter your water and settle on the glass, decorations and gravel at every turn. The water stays clean and doesn't become an issue during PWC's

 

[TomK2]

All the filters come with AC, but unless you need a proprietary cartridge for the filter that is only sold that way, you are free to use something else if you want.
There is a current poll on AA, and so far about two thirds of AA respondents don't use AC. Those 66% have substituted sponges, floss, or a porous bio-substrate for the AC. I am one of them.

 

[Mazdaman]

I've actually heard the carbon will not be active in as soon as 5-7 days. I am also one that does not use it unless removing meds from tank water. The foam does remove particules from the water and "polish" it but it also is biological filtration as the bacteria will build up in all the little holes and such.

 

[Toker95]

So with that poll (wonder I didn't come across it) and 66% of people NOT using activated carbon, sufficient bio and mechanical filtration really is fine, so long as its sufficient. And that makes sense, since so many filters, especially smaller ones really don't give you much options besides AC.

On the other hand, the carbon won't harm the beneficial bacteria in the tank, so long as its settled onto something, rather than in the water... fair statement?

 

[Fishyfanatic]

Using activated carbon won't harm the beneficial bacteria but something like ceramic rings is a better option because it can hold much more bacteria. As TomK2 said, all filters come with the AC, but you don't have to use it. You can simply just toss it aside and use it at a later date when you are removing meds. Just replace it with a bag filled with something else. And that something else can be whatever you tank needs (ie: Crushed coral, ceramic rings, peat).

 

[mattrox]

I like Aquaclear for HOB filers because you can get an extra sponge to fill the space instead of activated carbon etc.

 

[Jchillin]

My Fluval canister has four compartments. Each compartment is divided into two. That gives me a total of 8 media compartments. Since the AC is really not needed, I left two and used the remaining 6 for bio. Once the tank is established, if I need to "soften" the water, I can use peat, floss or whatever I need. I would estimate that in about 3 months, there'll be so much bacteria living comfortably in my canister that I could actually "lend" out media to immediately establish another tank.

 

[Mazdaman]

just the same thing I'm noticing with the "bigger" canisters. My xp3 has 3 compartments divided into 2 giving me a total of 6. I too discarded the carbon and added extra bio media. I am using to bottom 3 for sponges/foam, both the 20ppi and 30ppi. My next tray as the ceramic rings which I've read/heard nothing but good things about. The main reason is it is a really porous material and a ring so plenty of surface area for bacteria. The last two have floss and the polisher pad that came with the filter. (just another form of floss i think)

 

[Toker95]

Ok, somewhere along the way a thought popped in my head today.

Out of curiosity, AC is excellent for removing meds and other chemical contaminants from the water correct? What about things like plant fertilizers, e.g. a liquid plant fert of some sort. Do liquid ferts normally settle quickly to the tank bottom and into the substrate? Or does AC actually inhibit to some extent, the effectiveness of the ferts?

I say liquid simply because I presume it a pretty safe bet that the tablet versions should fall and stay near tank bottom, minimizes any interaction with the filter.

Just curious...