How log does actavated carbon last in fish tanks?

Question

I was looking for a scientific answer to the specifics of how it gets used up. I understand it depends on the load of organics and such in the tank. But I wanted to understand it more. I have a canister filter an ehiem 2217 and I have been putting the carbon filter pads that the company makes they are very expensive and I don't think they work very well at all. I was thinking of just getting some kind of pouch and dumping in a large amount of carbon. But I was trying to figure out if more carbon lasts longer because it gets used up less? I may have to do some research on this myself but I thought I might try this. i have a freshwater tank and it gets yellow fast it has 2 goldfish it's 29 gall. I also have a fluidized 300 gallon bed filter on it. I do gravel vacs 1 or 2twice a month. The gravel is clean.

Answer 1

The carbon lasts about 2-3 weeks.

Answer 2

A little yellow water is normal, so do not be to overly concerned with your water quality as you have good water maintenance procedures and quite honestly one of the best (yet under rated) bio filters available; the Fluidized Bed Filter. They are great. I have used these in many custom installations I have designed with very good results for both FW and SW. Your Eheim is also excellent!

The time carbon lasts will also depend on the amount used and the bio load. Anywhere from 1 week to 6 weeks is normal. I tended to use a small amount for my established aquariums (about a tsp per 10 gallons, or even less) so the duration was generally less than a month, which was fine as I do not like to use too much chemical filtration for a healthy tank with good filtration.

Here is a good aquarium information resource with more information including info about electrolytes and other water parameters:

http://americanaquariumproducts.com/Aquarium_Information.html

Answer 3

Carbon filtration isn't really for organics but for chemicals, it absorbes them by bonding the chemical into it. It will help somewhat with the yellow color of the water, but not entirely. Organics are taken care of by bacterial filtration, the bacteria that live in the filter, on the gravel and in fact every surface in the tank.

If you are having problems with only 2 goldfish in that size tank you probablly need to do more frequent water changes, maybe once per week. Also try using some poly wool in the filter, that works nicely for water "polishing" Tip: buy it at a craft store, MUCH cheaper than the stuff at petstores and no different.

Personally i only use carbon after the rare event that i need to medicate my tank (almost never)

as to how long it lasts, well it depends on your tank. Not more than 1 month would be fairly accurate.

Remember that if you DO use carbon any medications or chemicals you put into the tank will be removed by it, so remove the carbon to medicate.

Answer 4

Active carbon really only lasts 2-3 days in most cases.

Answer 5

1 month average.

Answer 6

i change mine every month