What is the role of carbon in a filteration system?

There are three different basic types of filtration: biological, mechanical, and chemical. That's providing a good enviroment for the nitrogen-eating bacteria, catching actual large format stuff, and removing unwanted chemicals.

Activated carbon is a good chemical filter. It bonds with an assortment of chemicals you might not want in your tank, tannins, medicines, foul-smelling organics, things that like to bond with carbon. Not everything likes to bond with carbon and somethings bond more readily than others.

Carbon is only active as a chemical filter for a few days. After that it makes a fine biofilter, not so active on the chemical side of the coin. No need to remove it if you like having it here, but its no longer chemically active.

The bonding is chemical bonding: once it happens its permanent under normal conditions. Things don't leach back out later.

If you have a specific reason for using it, its good stuff. Its not necessary on an ongoing basis: you don't need it unless you need it.

:dive2:
 
you really only need carbon if for example, you've been medicating your tank for disease with a chemical medication, and the treatment is over and you need to remove the chemicals, you would use carbon (plus water changes)

or if you are adding driftwood to your tank and its leeching tannins into your water and you want to remove them, carbon will work for that as well.

but in a normal, healthy, established tank, you really dont need carbon.
 
So if its chemical properties die out after a couple of days. Whats a more efficient type of media I can fill my filter cartridges with?
 
You can just replace it with a sponge or filter floss, which would increase the area for your biofilter. Depending on the needs of your tank you can also fill it with stuff like crushed coral or peat to change water parameters.
 
kyazh said:
So if its chemical properties die out after a couple of days. Whats a more efficient type of media I can fill my filter cartridges with?

Its chemical filtering capacity drops off after a couple of days. Its physical properties remain the same: it makes a nice biofilter medium, just as good as a sponge and it won't leach the nasties back out into your water. No harm in leaving it be.

The other options mentioned are also good: sponges floss, coral, peat (haven't tried that).

The main thin with carbon is that you don't need to keep buying it and swapping it out all the time. Use it when you (if) you need it to perform a specific chemical filtering job. Otherwise just rinse it in change out water as if it were a sponge and put it back until it gets too worn.
 
Aha, I see. So, I usually change my filter bags once a month. I can just re-use the carbon by rinsing it off with water? Then maybe I should keep the carbon in a second mesh type bag, make it easier to switch from bag to bag. Ive seen some white stuff thats usually right next to the carbon at pet shops, its ammonia or something like that? Whats that stuff for?
 
the white stuff you see is zeolite crystals (ammonia removing zeolite crystals). it suppose to remove ammonia, but i've heard good and bad about it. sometimes you can buy it and carbon mixed together, but if you have a biological filter (bacteria that eats ammonia and nitrite) then this is useless also. it might help while cycling a tank.
 
How often and how

I've been running my setup for almost 3 months now and I have a used filter from my brother's old tank. It has a carbon filter and coral sack, there both a little dirty and old. Should I change them and if so, I've read that you should only change 1 thing at a time in your filter?

I have two new replacements for both so any tips and advise on how/when to exchange would be great.

My tank is cycled (30g) with a combination of platies, cories,mollies,guppies.SAE, 2 ramhorns, angelfish and my water levels
are all good.

Thanks in advance. :hi:
 
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