lava rock vs bio balls

[Kague]

I guess I'm looking for more how big your output and input are

 

[Ulu]

Are you asking me???
I don't think so . . .
My system is small.
Try tagging the person you're asking.

 

[Ulu]

I also use poly floor stripper pads either whole in my large filters and barrel filters or cut into wedges in smaller w/d filters. They're more rigid than pot scrubbies and can be stacked deeper with less compaction.

View attachment 1129616

I built a smaller bio filter using this in the green and black varieties, with a sponge prefilter, and ran it for 2 years. I was very happy with the way it worked, but it tended to clog and became difficult to flush clean.

I also used these as a grow medium and it worked great, but once clogged they were a pain. I will only grow plants in loose media now.

 

[adamsfishes]

I don't see much benefit to using bio balls unless you have a really big filter and don't want a lot of heavy media. The light weight of bio balls is appealing for when you need to move it... but we're not moving this stuff very often. They definitely have less surface area than the alternatives like ceramic or sintered glass (what I'm currently using).

 

[OTp1144]

Okay I am trying to do this exact thing for my indoor pond. Help me out here. I'm stuck on multiple things. Like how big should my input and output be? What is the absolute best? What would you change about the design? ECT

I used an online tool to maximize my flow based on the pump I had. input was set by the output diameter of the pump itself, but output from the filter was maximized for that flow. Here's one site that helped me estimate flow and determine pipe diameter. (https://www.hy-techroofdrains.com/water-flow-through-a-pipe/)

While I've long since sold this setup and no longer am using it, one thing I didn't like about the design was the difficulty in backwashing and cleaning the media. I basically just opened the drain spout at the bottom and ran a hose through the top of the media until it ran clear. While this worked, it wasn't the most efficient or best method. I'm honestly not sure how I would want to improve on it, but I'd at the very least add a way to add a bubbler/agitator at the bottom to help break up debris and detritus during the backwash.

I will also say that pot scrubbies and matala mats are absolutely amazing as bog plant growing media. I have never seen taro or iris as big as the ones that were growing in this filter.