Fluval External 205 Carbon Bag

[Dextersmummy]

Hi, Ive had my carbon bag in my fluval 205 for several months and I think its not helping with a algae issue I have and it needs replacing? So for now as im not able to go to a store today I had some biomax from my old U3 is it ok to add this to the basket and throw the carbon bag? It already has a basket of the big biomax is it possible to add to much? can u use any sponge in there? like if I made my own instead? is the carbon bag nessasairy? thanks x

 

[DrRob]

Yes, you should be fine to replace the carbon with biomax, so long as it isn't massive quantities, as it'll still be offering some biofilter surface area, but nothing like the biomax should. Carbon is unlikely to solve algae issues by itself.

As for other sponges, in principle yes, although the surface area you'll get with the biomax should be better and you'll need to avoid extras like fire retardants and such like.

 

[fluttermoth]

Carbon can be useful; mostly for removing an excess of tannins from bogwood, or medications at the end of a course, but there's no need to run it permanently.

You can replace it with the biomax, or sponge; anything that will give lots of surface area for your bacteria to grow on. You can't really ass too much media, as long as it's not packed in so tightly that it restricts the flow of water through it.