Filter media

[mattelatte]

What do you recommend in your HOB filter on a 20 gallon tank. Right now i just have the sponge and biohome in it. It is a clearview 50. Do i need carbon or polishing. I will be running pressurized CO2 within the next few weeks. There are some platys and mollys in it right now but they are coming out and it is strictly going to be plants only.

[Fishypastor]

Plants and root systems and leaves and mosses are all going to be extra surface area (and very bio friendly surface area) for all kinds of wonderful bacteria. To boot the plants are going to be consuming Nitrogen compound... so your need for filtration is likely going to go down. I have an el cheapo HOB filter from ages past on my 20 g planted and all I have in it is a chunk of foam to catch the "griblets" (that's the technical term) and a handful of lava rock.

I find that planted tanks tend to gum up filters pretty quickly so you want to make sure water can flow... more filtration media might mean more and more cleaning.

[hello_rockview12]

Honestly, I'd go with just foam or floss and some of the bio balls or bio media and never replace any of it, unless absolutely necessary! The foam can be rinsed in aquarium water every month or two and the bio media is essentially good for years and years.

Carbon is unnecessary and can actually work against you if not replaced often enough. I'm of the opinion it's mostly designed to sell people refills, although it does have it's purpose on occasion.

[alexmtl]

Actually I do not add filter media to the inside of the HOB. I add a sponge to the intake (outside).

I had thought about adding bioballs or plastic media to the inside but I just have not done it. I let plants grow on the sponge filter.