How often should the carbon in the filter be changed? I have 2 canister filters in my tank. I last changed the carbon about 4 months ago in both filters (a week in-between each filter).

I think the tank went through a mini cycle because there was a bit if algae growth after the carbon was changed, maybe I should have waited 2 weeks between filters.

I think it may be due again, NH4 and NO2 are 0 still but I think I should think about changing the carbon again.

__________________
45g pentagonal
4 Swordtails, 2 dwarf Gouramis, 5 Mollies, 1 Rainbow Shark, 6 Molly fry 6 zebra danios

88 gal Malawi tank
4 Yellow labs, 1 Baenshi, 2 Borleyis, 3 Trewavas, 2 Livingstonis, 1 Venustus, 2 Green Terrors

I don't use carbon so I would say .... never. :o)

If you use carbon you shouldn't use it for more than a month and some would say that it is only effective to about 2wks. If it is a separate part of your filtration and your filters aren't carbon impregnated, then it won't matter when you replace them. It will not affect your bio filtration.

Most people that have had tanks for years don't use it. It really is only needed to get something out of the tank.

I dont change my media.I have canisters and neither has carbon.I do rinse the filter floss in tank water every few months.Other than that,they get ignored.

__________________
http://bountifulbettas.blogspot.com/

"Come to the dark side....we have cookies...and filters/heaters/and water changes!"

Yeah I usually only run the carbon to do specific cleaning of the water. It does make a difference if you have "bad" tap water and are doing water changes often. Also keep in mind that carbon can be cleaned and recharged.
And I never do a complete cleaning of any other media.
Even fitter cartridges are only rinsed or swirled in a bucket of WC water.

__________________
"Buddha in your tank"

My filter uses a Sponge, Carbon and Bio-max.

For the Carbon, I change it completely once a month. (I rinse the new carbon in tap water first, then swish it around in the dirty fish water I've siphoned out of the tank during the water change to get some good bacteria in it, and put it in the filter). During the weeks between changing it, I just swish it around in the dirty siphoned water to give it a quick rinse.

The sponge I change once every 3 months. I wring it out and squeeze it in the dirty siphoned out fish water every week in between changings, (to get larger pieces of debris out and to keep the good bacteria in it as well). With a new sponge, I rinse it in tap water, then swish it in the dirty fish water before putting it in the filter.

The Bio-max I change once every 3 months. I swish it around in the dirty siphoned fish water every week in between changings as well. The new Bio-max is also rinsed in tap water and then swished in the dirty fish water before put into the filter.

During the month that all 3 media are changed in the same month, (which is every 3 months), I do them on different weeks. I also never change a media on a week where I clean the filter for regular filter maintenance. So for example: Each week has 4 sundays, so the 1st Sunday I will do the sponge change, the 2nd Sunday I will do the filter cleaning, the 3rd Sunday I will do the carbon change and the 4th Sunday I will do the bio-max change. During a regular month when it's just the carbon being changed, I will clean the filter one Sunday and change the carbon on a different Sunday. (Sorry, I know it's kinda' long, but just trying to be as detailed as possible). I've never had any problems changing/cleaning media this way.

Lol, I hope this helps and doesn't give you a headache!

__________________
20g Heavily Planted http://www.aquariumforum.com/gallery...00&ppuser=8981
36g Bow Front Heavily Planted http://www.aquariumforum.com/gallery...00&ppuser=8981

Carbon can be recharged?

Well, it can be re-cooked at temps around 4000deg, and that makes it "new".
But that's usually a little impractical.
Carbon, or Charchol is a micro porous filter. What I do is give it, a really hot washing and rinse, and although I'm sure it's not completely renewed. It does seem to extend the life and usefulness of the carbon. But if I've used it after a medicinal treatment, I toss it.
It's cheap enough that you probably do need to do this, but I guess I'm a cheap SOB...
Keep in mind, and this is for Holly.
That your filters contain good bacteria, and when I say that I rinse them off. It is only to get big stuff off, plant matter, poop, some algae, etc... And maintain proper flow. I personally feel alot of people over clean their tanks, and that's why people always have ammonia spikes, or nitrate/ nitrite spikes or other problems. There is a balance, which of course is what your asking. I'd say watch the flow of the media, if it starts getting restricted, then clean or replace. Another thing I do is cycle filters, keeping one "cleaner than the other. This helps insure a good biological filtration.

__________________
"Buddha in your tank"

Don't worry, I don't scrub the filter until it squeaks, lol. I rinse it to get the big chunks of algae, food, poop, etc... out of it and use a bottle scrubber to clean the intake a little bit (it gets pretty gunky), but I definitely do not clean all the stuff out of it. Woot for good bacteria!! (As for the media, I usually notice that by month 3 the sponge and bi-max are pretty disgusting, so that's why I change them at that point). Carbon I was just always told to do once per month. Thanks for the tips though!

__________________
20g Heavily Planted http://www.aquariumforum.com/gallery...00&ppuser=8981
36g Bow Front Heavily Planted http://www.aquariumforum.com/gallery...00&ppuser=8981