Replacing Carbon Advice

Meader85 said:

Hi there! I'm new to the hobby having set up my first fish tank 6 weeks ago, with fish in for around 2 weeks now. Its a 60 litre with carbon inside the filter sponge. What I'm wondering is when is it best to replace the carbon? Are there any tell tale signs to look out for that would indicate to me when its best to change it? I've read online that it should be changed every month but is that true? Do the bacteria in the tank live on the carbon as well which could cause problems if I fully replace it?

Any advice here would be really helpful!

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EllRog said:

Carbon is useless unless you're removing medication from the tank, you'd be better off replacing it with sponge of bio cartridges I've never replaced any of my filter media, I wouldn't want to lose the beneficial bacteria

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essjay said:

Those bioballs are quite large, would they fit in your filter?

Can you tell us what make your filter is so we can see what would be the best option.

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Aqua Range Aqua Internal 200 filter

Great prices on Aqua Range Aqua Internal 200 filter : find out more and buy online or instore.

www.fishkeeper.co.uk

essjay said:

I used to have the smaller version of that filter in my betta's tank. It's a sponge with a hollow filled with carbon. In mine there was a lot of sponge and not much carbon.
I just threw away the carbon and filled the hollow with a bit more sponge. Those bioballs definitely won't fit in the hollow but you can chop up a bit of sponge to make it fit. Or just leave it without anything.

Then just wash the sponge every couple of weeks by squeezing it in the old water you take out during a water change. Sponges last for years and only need replacing when they literally fall apart.






Looking again at the description at that 'crystal clear' cartridge - I hate it when manufacturers put zeolite in a filter. All it does is remove ammonia and starve the filter bacteria, then it gets full, stops removing ammonia and there aren't enough bacteria to cope so the ammonia level shoots up

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essjay said:

The reason manufacturers put carbon in filters is because it's a hangover from decades ago when filters were just about all carbon; because it's cheap but they can charge a lot for it; and they want you to keep replacing it to make money.

Carbon adsorbs organic things - the brown colour that leaches from wood and medication. And it does get full which is why it needs replacing if you want to use it. But you don't need to replace the entire media in the filter, you can buy a bag of carbon granules and just replace the carbon if you want to keep it in there.


Flourish Excel is glutaraldehyde, a powerful disinfectant. Even at the recommended dose it can kill plants and harm fish. I won't allow this chemical anywhere near my tanks

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Meader85 said:

Ok thats concerning regarding Flourish Excel. What brand/product would you recommend to help feed my plants? I don't have a CO2 system in place and hadn't really planned to.

I have been using this product as well. Will this be sufficient? https://www.amazon.co.uk/dp/B00CEZGJS6/?tag=

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essjay said:

The reason manufacturers put carbon in filters is because it's a hangover from decades ago when filters were just about all carbon; because it's cheap but they can charge a lot for it; and they want you to keep replacing it to make money.

Carbon adsorbs organic things - the brown colour that leaches from wood and medication. And it does get full which is why it needs replacing if you want to use it. But you don't need to replace the entire media in the filter, you can buy a bag of carbon granules and just replace the carbon if you want to keep it in there.


Flourish Excel is glutaraldehyde, a powerful disinfectant. Even at the recommended dose it can kill plants and harm fish. I won't allow this chemical anywhere near my tanks

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essjay said:

Not Flourish Comprehensive Supplement, but Flourish Excel, the 'liquid CO2'.

Unfortunately virtually all liquid CO2 products contain glutaraldehyde. The only options are - high tech, dose CO2 gas; low tech, let the fish and substrate bacteria provide the CO2.



Re the filter in question - I used the Aqua Internal 50 in my betta's tank a few years ago. This is the sponge in mine

View attachment 111575


There is a hole down the middle of the sponge which was filled with carbon and a small sponge plug to stop the carbon falling out. The sponge is fine on its own. You don't need carbon, but if you do want to use it, just buy a bag of carbon granules, throw away the current carbon and put new carbon in the hole (wash it first, carbon is dusty).
There is no other media in my filter besides the carbon filled sponge - is yours the same (only bigger)?

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