No carbon in filters? (cross posted to freshwater)

[coolchinchilla]

<tongue-in-cheek>
I've recently heard that some people don't use carbon (or any other chemical media) in their filters. 8O Is that really true? It seems that carbon is ubiquitous in this hobby. Every filter sold (ok Whisper filters) comes with carbon. Almost all the beginner info on fish tanks talk about using carbon in filters. Even acknowledging that the carbon is only good for a week at best, it is supposedly a great place to house biological bacteria.


And some people don't use carbon?????

Seriously, a few questions about carbon use:

1. Why don't you use carbon?
2. If you don't use carbon, do you use some other chemical media?
3. If you don't use carbon, how do you keep your ammonia, nitrites in check?
4. Are there setups where carbon is a bad idea?
5. Are there consequences to using carbon? (leaching stuff in water?)
6. Are there consequences to not changing the carbon very often?
7. Do you use carbon for a brief time for say an ammonia spike or to polish the water?
8. Do salt water people use carbon?
9. What would you recommend to someone who is a beginner -- some experience but a beginner with keeping fish with regard to carbon use?

(I have a community tank 15-gal running for a year and a 30 gal tank of malawi cichlids -- running for 2 months.)

Thanks in advance.
coolchinchilla. (be sure to drink a lot on these HOT days!)

 

[malkore]

I will answer your questions with SW in mind.

1. I only use it occasionally to remove yellow discoloration in the water, due to not doing a water change frequently enough (this isn't common for me though)
2. Nope.
3. Carbon doesn't do squat for ammonia or nitrites. I think you're mis-informed on the purpose of carbon.
4. In SW, none that I'm aware of.
5. As long as you change your carbon at least every 7 days, this is a non-issue.
6. Yes, carbon only lasts 5-7 days. After that it doesn't absorb anything, and if it sits too long, it may start to break down, and could leech phosphate into the tank.
7. Carbon does nothing for an ammonia spike. Carbon is good for removing yellow'd water from old saltwater, and to remove odors. That's really it's sole purpose for marine tanks. Carbon can remove medications, but you don't medicate display tanks.
8. ...
9. Its not a necessary item.

Also, whisper filters are pretty low quality. If you want a better HOB that doesn't force you to use a cartridge based filter media, look into Aqua Clears.

 

[schoeplein]

To answer your question - to use carbon in a continous fashion, someone figured out the proportion of carbon required per gallon of water. I think it calculated out to around 30lbs for a 75g tank. This is for use as a substrate in your sump or other canister type device. An excessive amount.

And I think carbon lasts a lot longer than most people give it credit for. Its just that typically when you pull the carbon pouch out, or remove the carbon particles, tons of detritus and other buildup that hasn't been removed by other means before reaching the carbon destroys its effectiveness.

And much the same reason people are abandoning biowheels, its another supposed "nitrate factory" (probably for the reason I mentioned above).

Carbon kicks so much butt for removing odor, and making your water super clean. Carbon and UV sterilization I would use on a tank that is established and you're not much interested in things in your system growing excessively (UV prevents featherdusters from spawning, prevents most algaes from growing excessively).

As for leaching phosphates into the tank, I believe that is a little misleading. Previously carbon used to have a manufacturing process that left trace amounts of chemicals in the product. This manufacturing process is no longer kept - modern carbon should (emphasis on should) be devoid of any excess chemicals.

 

[coolchinchilla]

Thanks for the tips! It helps a lot.

coolchinchilla