DIY Biomedia? (converting old HOB)

**chocological** · 09-14-2012, 10:30 PM

Okay. So on my 20g tank, I have a HOB rated for 40 gallons. That's great and all, but I'd like to increase my bio filtration. I have a second HOB that I'd like to use, it's a "Top Fin" rated for 20g. I'd like to use the Top Fin HOB as just a bio filter. It was made to accept only filtration pads, but I was wondering.. In the reservoir, could I add some objects that bacteria could lodge on to? Perhaps some rocks, or I could pick up some bio balls from the pet shop.
Thanks.

**genocidex** · 09-14-2012, 10:36 PM

well you could get ceramic bio media and some media bags. if you get them to fit im sure the filter will still work. or you can stuff it with filter foam. a favorite is AC's foam pads... they do hold a good bb. but i llike the ceramic rings the best.

edit: heres a good media like i was talking about
http://www.petsmart.com/product/inde...ductId=2753122

media bags shouldnt be more than a dollar or 2

**chocological** · 09-14-2012, 10:39 PM

So I could just throw them into the reservoir in the HOB?

**dbosman** · 09-14-2012, 10:45 PM

Take a good look at the filter and how the water flows into it and out of it.
Some lend themselves to just dumping bio media in. Others can take a large chunk of foam filter material, but not bulk media.

Top Fin brand covers more than one style of filter. Some were designed for filter cartridges only. Some of those can take DIY adaptations.

Here is a filter cartridge frame I'm liking at present.
http://www.drsfostersmith.com/produc...2&pcatid=11352

They come in several sizes and readily take off the shelf quilt batting, or a batting sandwich with bio media inside.

**Indian Woods Angels** · 09-15-2012, 12:41 AM

Both answers above are very good.

You do not want to just toss media into the back of the filter because you may cause interference of the impeller that is producing your water flow through your unit. You should use a media bag or a filter pouch bag.

**chocological** · 09-15-2012, 02:48 AM

Thanks for the info guys. There is a bit of room in there so I'll explore the foam option.

**Lady Hobbs** · 09-15-2012, 05:02 AM

That's what I did when I stopped using cartridges. I got an Aqua Clear foam sponge, cut it to the size to fit in the back on the filter box and added a bag of biomax on top. I didn't even use the biowheels.

**RainbowDragon28** · 09-18-2012, 03:34 PM

Bio-media like Bio-glass that you can get by the liter to add as a customization to any filter is easiest accomplished by using in conjunction with fill-in-your-choice- media mesh bags and a pre-filter IMOP. I used one of those mesh bags and put bio-glass and shaped it into a column to fit in-between the filter cartridge and bio-wheel in my penguin 100. I feel this will increase my filter capacity better than a sponge and won't impede on water flow. Also, I'm only using cartridges still because I bought a 12 pack and need to use them up.