View Full Version : Do you really need a carbon cartridge in your filter?

02-22-2006, 7:04 PM
Do you really need a carbon cartridge? Shouldn't the bacteria in the tank take care of that problem? Shouldn't you just need mechanical and bio media?

02-22-2006, 7:13 PM
Carbon cartridges only last for a short time removing organics and some metals. However carbon is a good substrate for your biological filter which is the real workhorse of the filtration system. Understanding how filtration works and how to maintain a healthy biological filter is key to success with fish keeping. Learn how to do this and you will be rewarded 100x. Good luck and best wishes.


02-22-2006, 7:15 PM
AFAIK, once the carbon has expired, after a while it will start to leach toxins back into the water. ANd i remember reading somewhere that carbon dust interferes in fishes respiration or something.

02-22-2006, 7:21 PM
I don't use it, but keep one on hand in case I need it to remove meds or something.

02-22-2006, 7:24 PM
Don't use it. Don't need it. If I had meds to remove I might. There are much better filtration media out there to use to colonize bateria than carbon.

02-22-2006, 7:38 PM
so are you guys saying it's better to replace the carbon filter bag within aquaclear filters with another bio stone bag? so instead of:

mechanical (sponge) ->chemical (carbon) -> biological (bio stone)

in aquaclear 3 stage, it's better (or rather equally good) to have:

mechanical (sponge) ->biological (bio stone) -> biological (bio stone)


02-22-2006, 7:49 PM
im also wondering about this as i have a whisper 10 on my tank right now with a bio bag thats been in there for a month. Im thinking i should just get rid of the carbon inside the bag. I already stuck some extra foam in behind the bag to help with bacteria after i partially lost my bio filter last weekend. Plus i have a new aqua clear 30 on the way and i need to know how to transition to the bigger better filter??

02-22-2006, 7:51 PM
i have ALWAYS used a little carbon in my fitlers. It is not made for bactiera growth as some have siad. it is almost like doing a chemical teatment on your water.

I do have a aquaclear filter on my 10 gallon goldfish tank. I run two sponges and 1 section of filter floss. I find it works GREAt, i change the filter floss once a week since the stuff is so cheap. and the sponges get a good bactiera culture going.

In my 30 gallon community tank i have a Hydro Bravo filter running. The hydor filters have a small basket on the front of them for whatever media you want to place in there as a extra bonus to what is already in the filter. Once a week i replace the carbon that i ahve put in there, it is so easy to take in and out and to change. It is great. I ahve always used carbon in my fitler and from what i see, it does not hurt.

I know some people say that activated carbon will leech stuff BACK into your tank, BUT, this would not happen over a long pieord of time. If you left your carbon back in for a month or more. I change mine after a week. AND becuase my filter is nicely designed, i can take it out easy if i need to add meds.

Anyway, those are my two cents. :coffee2:

02-22-2006, 7:52 PM
............... Plus i have a new aqua clear 30 on the way and i need to know how to transition to the bigger better filter??

Run the new filter on the tank at the same time as the old filter, this will help establiah a bactiera culture in the new filter.

02-22-2006, 8:07 PM
so are you guys saying it's better to replace the carbon filter bag within aquaclear filters with another bio stone bag? so instead of:

mechanical (sponge) ->chemical (carbon) -> biological (bio stone)

in aquaclear 3 stage, it's better (or rather equally good) to have:

mechanical (sponge) ->biological (bio stone) -> biological (bio stone)


I have mine set up this way:

Mechanical sponge > thin layer of Fine filter floss (more mechanical) >biomax stones and additional Seachem Matrix biological media

02-22-2006, 9:31 PM
So, what you are saying is, I really don't need carbon except for removing meds? I absolutely HATE having to spend money on filter cartridges for my penguin filter EVERY month, and then having to buy seperate carbon for my aquaclear.

So, if what you are saying is correct... should I just leave the biofiber in the filter, such as whats included with my generic 250gph filter, and just run the biowheel filter and sponge filter in my 29, WITHOUT THE CARBON CARTRIDGE, just the wheel and sponge filter, and then replace the carbon in the aquaclear on my 40 with another bag of bio max?

I mean, fish urine is ammonia, correct? So the bio bacteria should remove it, and the need for carbon is non existent other than to remove meds.. So should I just keep a few on hand just in case?

Also, what is the need to replace the foam in the aquaclear filter? I can see rinsing it off, but other than that it shouldn't degrade THAT much, and harbors beneficial bacteria. Just seems like a money making scheme to me.

I want to make sure that I can, in fact, get away without using carbon before I take it off my tanks. I don't want to have a massive spike or anything. Also, what do you do for mechanical filtration? I mean, that is the purpose of those cartridges you buy for the penguin filters. Do you use something else? Or just let it flow through and dip it out with a net?

02-22-2006, 9:35 PM
Most of us here do not replace aquaclear foam filters on any regular basis at all. We squeeze them out and rinse them in a bucket of tank water and reuse it. Many people use that sponge for several years. . . .

The only disposable media I use is hypoallergenic polyester quilt batting that costs just pennies to cut a double layer to fit on top of my sponge. If you don't want to buy filter media from the sewing section of Wal-Mart, most fish stores sell the same stuff as "filter floss" for a higher price (but even that is incredibly cheap compared to replacement cartridge filters)

I still have the original carbon bag from my aquaclear just sitting there in case I ever have some reason to try to remove toxins or medications from the water.

02-22-2006, 9:39 PM
Sounds great. As soon as this month is up, I'll be sure to remove them. I guess instead of using a filter cartridge, I'll buy some quilt batting from wal-mart. I think it's more than I will ever need to use for $2.00. It didn't make sense to replace the foam every 2 months. Seemed like a waste of money. Same with the biomax. Do you really need to replace it every 3 months?

Also, I should put the quilt batting where the carbon used to be? How often do you replace it?

02-22-2006, 9:43 PM
I usually just blast my penguin cartridges clean with some high pressure tap water weekly. No worry about damaging my biological filter since the biowheel takes care of that. The only time I run carbon is when I need to remove medications or some other specialty purposes such as new fish or insurance. Whenever I add new fish to the tank (after QT of course), I sometimes like to add fresh carbon to the filter to ultra polish the water. This ultra polished water helps the new fish adjust to the tank after the stress of moving and also by reducing organics, decreases the workload on the biofilter allowing it to cope with higher fishload. The insurance reason is rather simple. You can't always watch every guest during a social gathering so the carbon takes care of any mishaps that might occur with your guests and the fish tank.

02-22-2006, 9:50 PM
Sounds good rrkss. By blasting the penguin cartridge though.. is the carbon still active? Or can it leach toxins into the water? I thought about trying to find a way to remove the carbon and just have the cartridge for mechanical filtration, but I couldn't figure out a way. I figured this was why the quilt batting was so good. What do you think? Could you cut a hole and take the carbon out? Then just run the cartridge to catch debris and nothing else?

I'm really happy to know that I don't have to have carbon. I have 5 extra filter cartridges for my 250gph and the penguin, just in case. Like you said, good insurance when adding new fish until my bio filter can catch up. Plus I have 3 extra carbon bags for my aquaclear. I think I am just going to put an extra bag of biomax in there. How often do you think I need to change that? I mean it harbors bacteria, right? It should degrade to the point of replacing in less than a year, right?

02-22-2006, 10:08 PM
Check out www.drsfostersmith.com if you want to save money on filter replacement cartriages. Been ordering from them for over 10 years and I have had excellent luck with them. I bought a filter from them for 40 bucks and online a place wanted close to 80 bucks. If you get on there site, you can have them send you a magazine.

02-22-2006, 10:18 PM
I've been getting there magazine for quite some time now. I knew they had the 3 stage filter cartridge for the penguin filter, but if I could get away with a carbonless filter cartridge that I just rinse and reuse, then I'd much rather go that route. The only place that I have ordered from online is Petsolutions.com and I must say I am extremely pleased with the service. It got to me in 2 days and I paid for just the standard shipping. 10 bucks on a 130 dollar order. I bought the aquaclear 70 for 20 something dollars, a strip light for 60, a glass cover that doesn't fit, lol, for 23 bucks, and all the extras for my aquaclear for around 10 dollars, a skimmer for 10 bucks, and then last but not least my sponge filter for a 40 gallon for 5 bucks. All in all not bad prices and definitely quick shipping. Drsfostersmith.com usually has higher prices on equipment, but lower prices when it comes to fish and food and other supplies. Thanks for recommending them. I know I like their specials alot, and I certainly get alot of good ideas out of their magazine.

02-22-2006, 10:22 PM
Carbon leaching out the toxins in aquarium conditions is a myth. Carbon will only release the stuff it took up under an extreme in pH and temperature. I doubt anybody keeps their tank at 2000 degrees with a pH of 12. I also don't think anybody has their tank in an oxygen free environment. Anything absorbed by the carbon will stay in the carbon under normal conditions. This allows you to change the carbon whenever you want fresh carbon without worry. I don't open up my penguin cartridges to remove the carbon just blast it clean without any worries.

02-23-2006, 1:14 AM
The problem with the carbon is it looses it's effectiveness after a couple of weeks, so if you think you are benifiting from it...you really arent.
Except as a media for biologic filtration, and there is better around. You're not hurting anything...just spending $ you don't need to.

02-23-2006, 7:00 PM
You know how much I love spending money that I don't have too haha! I dread buying those filter cartridges. I'm so happy now knowing I don't have to. I guess i'll just leave the carbon cartridge in there and let me it build up bacteria. From what I've read, it won't release the toxins. I'll just blast it like you guys have said with hot water, or lukewarm to preserve the bacteria. Thanks again for all the help!

02-23-2006, 8:23 PM
Carbon can leech but not under conditions that fish can live in so no worry there. Used carbon really won't affect meds of any sort. And carbon lasting a week would be a miricle.

Will it hurt to use carbon, not at all. But it will hurt the pocket book if you want to use carbon to its full advantage as that would mean new carbon each week. And frankly weekly large water changes will do most things that carbon does anyway.

02-27-2006, 12:15 PM
I purhcased some quilt batting yesterday. Some premium fiber fill. I want to put some in my 100gph HOB filter as well as my 250gph HOB filter. How much do I put in? Do I need to put it IN something? Or do I just pull some out and shove it in the filter? Does it need to be replaced? Is there anything else I need to do to get mechanical and biological filtration?

It's got the bio media that came with the filter... that little porous pad. Do I just need to put it and the fiber fill in there and let it run?

Also, how should I put it in my aquaclear 70 when the carbon runs out? I'm going to replace the carbon with the fiber fill.

Thanks guys!