freshwaterguy

While my friend was looking after my Rio 125 tank as mentioned in a previous post, I have now discovered when changing the white filter pad that is changed weekly that under the carbon filter which sits directly below the white filter media was another old Carbon filter - which my friend had left in the tank and just put a new carbon filter on top of the old one every 3 weeks! this old carbon filter has been in the tank apparently 3 months.

During this time I lost a few fish, I would like to know how bad this would have been for the tank, as I understand it a carbon filter will rid the water of impurities and after 4 weeks will leach nasty stuff into the water.

Obviously I cannot bring back the fish that died may they R.I.P but I would like to know what effect this would have had?

Thanks

clinton1621

Basically carbon once its saturated (which can take as little as 48 hours) just leaches out minimal amounts of whatever it absorbed, it usually retains most if not all in some cases though. It also serves as a good media once its not active anymore, bacteria will grow on and in it and eat a lot of the waste thats built up on and in there. Unless you are worried about removing meds or some kind of toxic metal (not sure why that would be a problem with most water anyway) then carbon does relatively little to actually help your tank, it actually will remove a lot of your trace minerals that keep your hardness and ph stable, and also vitamins and minerals that your fish use.... not to say it removes so much that its hurting anything initially because it wears out quick, but with constant use and frequent replacement it could cause vitamin and mineral defficiency in your tank. In my opinion you would be better off to use bio balls or some other inert media that will build up higher bacteria levels and doesnt have to be constantly replaced, and then you also have no worries about any leaching by the carbon.

morganrules

i dont exactly know but sorry to hear about your fish

freshwaterguy

Thanks for your replies clinton and morganrules - I have been trying to get my RIO125 back to what it was before I went and left it in my friends hands.