# Is my fertilizer getting filtered out?



## Fuzz (Jan 27, 2012)

I know it is a highly debated subject in the planted tank world, but I might find enough scientific facts that lean towards an "answer". The question is this : Does carbon(the kind used in filtration) remove or filter out micronutrients/macronutrients? 

Carbon traps small particles, but I've also read that carbon eventually gets "clogged" and stops doing its thing. This could be why the filter companies tell you to replace your cartridges and carbon media once a month. Some filter maintenance instructions tell you to wash the carbon every certain amount of time(a month?). If all my fertilizers are just going to get filtered out, then why even bother dosing them? If carbon removes the fertilizers, why use carbon in my filter?

If this is the case, then you could just not replace/refresh/rinse the carbon media and be okay...but there wouldn't be a point in keeping the carbon in your tank because it isn't functioning anyways.

If you are overdosing your tank with fertilizer, the carbon could potentially be sucking up the excess. That's a good thing and can help control algae, but you really wouldn't know if you are overdosing or not unless your fish start dying or your water parameters start changing(might not be true, but it's a thought). 

Is there a way to test how much macro/micro nutrients are in the water column? If so, I'm almost willing to do a test where I run carbon for a month, measuring my nutrient levels every day. After that month, run the exact same setup with the exact same dosing(same fish, too) and remove the carbon from the equation. This way, the carbon in my filter is the only variable and its tested every day over the course of a month. If there is less nutrients in the water column with the carbon than without the carbon, we'll be on to something. If the levels of the nutrients during the carbon test gradually increase over the 30 days, that also leans towards the carbon getting "clogged" and becoming almost useless after a month or two. 

I have a H.O.T. Magnum so adding/removing the carbon is easy. Since I've read that carbon could potentially remove the fertilizers from my water, I didn't add the carbon to my filter. I could easily run this experiment in my tank as long as there is a way to test the nutrients that are provided in my fertilizer. It would be interesting to find out whether the story is made up, or actually true.

Any ideas or comments?


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## Obsidian (May 20, 2007)

I do not use carbon in my filter unless I need to remove medication. Otherwise it serves little purpose.


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## Fuzz (Jan 27, 2012)

Yeah, I guess it makes sense. Carbon pretty much just removes chemicals and stuff that makes the water look cloudy/dirty anyways...Since planted tanks benefit from more frequent water changes anyways, I don't really need to worry about it.

That being said, it would still be nice to know the truth about this.


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## grogan (Jan 23, 2011)

Carbon in a planted tank is a bad idea. I personally don't use carbon because I feel it effects 2 aspects of my planted aquariums. 

1st:
Im on the side of it does mess with your ferts. Okay, so my heavy dosing of fertilizers gives my aquarium a green tint and is not always crystal clear. I counteract this by doing weekly water changes and not letting the green tint worry me. Flourish tends to do this. 


2nd:
I use pressurized co2 and carbon removes carbon dioxide. Essentially making my expensive co2 system less effective. 

Long story short, activated carbon is useless in my opinion. I have it on hand for removing medications but other than that its a waste of money.


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## Amelia26 (Aug 6, 2011)

ok... so heres a stupid question. what do u have in ur filter? maybe a sponge? i have a HOB on my new 10gal. what do i replace the carbon filter out with?


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## Obsidian (May 20, 2007)

I have a sponge and bioballs, and that's it. Some add filter floss for clarity. If you have the "cartridge" type HOB (whisper, for example) you can pull out the cartridge and put in the sponge and ceramic balls. 

When I did this to my cartridge style filter I used the Aqua Clear sponges and bioballs for the AC 10. You will want the sponge to be a solid fit, but not tight. You can find sponges from other manufacturers as well, just the AC is common and easy to get a hold of. You should not need to ever replace the sponge- just swish in used tank water at time of cleaning and put back in. 

For filter floss they sell that in stores as well, usually in big plastic bags, then you just cut to fit and change out when it gets clogged.


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## Amelia26 (Aug 6, 2011)

ok cool!!! thanks!!!!!!


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## grogan (Jan 23, 2011)

In all my canisters I simply fill the empty compartment with more ehime bio media..lots of it!


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## Fuzz (Jan 27, 2012)

it's always good to get responses. seems like a lot of people in this forum are pretty helpful so far. i'm liking it


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## giggitygiggity (Sep 14, 2011)

Wish I woulda known carbon removes CO2.......



Gonna take the carbon out of my filter right away lol


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