Hi. I have been watching Solid Gold a lot. I noticed that in her tanks and pond she has this sort of sponge filter/ aeration device. I was wondering if anybody knew exactly what it was and where to buy them.
If you start at around minute 4 she goes over filtration. It looks like she is just using a natural sponge, then ceramic rings, and filter floss. She also has some links listed in the description of her video, but it doesn't say specifically which sponge she uses. But it might at least give you some other info that way.
Maybe she has more specific info on her FB or twitter.
Edit: oh were you talking about the circular sponge inside the tank? Not the HoB media? You can just google sponge filters. There are tons of options to choose from. DIY guy did a whole video on sponge filters too.
Swisstropicals makes nice ones from poret foam. I use the poret foam exclusively for my sponge filters and any applications I use foam. It works amazingly in my wet/dry tower its much more efficient than a fluidized bed. Hardcore Koi keepers use it a lot over fluidized beds