Changing filter whilst cycling tank

[Sam77]

Hi, I am currently 5 weeks into cycling my tank (3 weeks with my axie in). I have a fluval u2 filter which I have not cleaned yet (I read somewhere not to clean it whilst the tank is cycling) but I just read in the instructions that the carbon needs to be replaced every 2 weeks? Firstly, is this necessary? I am sure someone on here wrote that if the carbon is not changed it can dump everything back into the water. But should I change itbwhilst the tank is still cycling, as I don't want to slow the cycling? Also changing the carbon every 2 weeks is going to work out expensive! I would be grateful if anyone could help me by letting me know how often you all change yours.

Thank you

 

[Sam77]

Can anyone help??

 

[carsona246]

carbon is totally unnecessary, I only use medication for very specific reasons(such as removal of medications). The filter companies tell you to change out your media more often than necessary. I probably clean my filter out once every 6 months, and that's only for the mechanical filtration. If you do clean out your filter, make sure to only use old tank water to clean out the bio media. But I don't recommend any filter cleanings until the tank is cycled

 

[Sam77]

Thank you for putting my mind at rest!

 

[carsona246]

just realized I said only use medication for medication. What I meant to say was I only use carbon to remove a medication

 

[Gromky]

Agreed here. Do not replace carbon as they say. In fact, I would say only replace filter media as it significantly deteriorates, and never too much at one time.

Activated carbon works as a chemical filter, for a while. It clogs up with organics as it removes them. Back when I did research, the standard way to reactivate carbon was to wash multiple times with pentane and hexane, then bake/evaporate the solvents off...not something you can do at home. So they say to replace it.

Luckily, all the little nooks and crannies that catch organics are also great for bacteria, which are what you really want. Chemical filtration is touchy, short term, and Carson has given the only reason I can think to really want it. But the carbon filters turn into pretty good biological ones. I tend to just use sponge, bioball/ceramic beads, and filter floss...but carbon packets are ok too.

 

[Sam77]

So I can just leave the carbon bits in there and they won't do any harm? I looked into replacing them with sponge, but the sponges won't fit in the carbon slot if you see what I mean. Thanks!