Media Question For HOB

[Coolysd]

Hey y'all!
I have a couple of big hob filters and I don't want to have to purchase the cartridges. Been doing some research on DIY media and read that there is a certain order in which it needs to be placed. I've also read conflicting answers as to the order.
Can someone please explain this process for me? Also any tips on "building" them would be greatly appreciated!
Thanks a bunch!

 

[Rocky998]

So it goes, mechanical filtration first (where the water hits first), biological filtration second, and chemical filtration last (personally I don't use chemical filtration in my filters and wouldn't recommend it)

 

[Uberhoust]

Similar to above.

Water in
Medium coarse sponge
Polishing Media (typically not used, only for special cases, like a substrate change)
Bio Media (I use as much as the filter will hold, aerated surface area is the only quality aspect I consider)
Chemical Media (Typically not used, special case phosphate scrubbing, ammosorb for emergencies)
Water out

99% of time only use the sponge and the biomedia. I find when things are going well you don't need any water polishing.

 

[Coolysd]

Thank you both for your explanations!! Being a newbie, I had no idea what the order was or that there even was one! And come to find out, I had it all wrong!
I am having issues with the cycling (see my previous post) so I'm just looking at every possibility so I can get it back going cuz it seems to have come to a hault.

Thanks again for your expertise!!

 

[plebian]

There is a LOT of misinformation about filtration in general, and filter media specifically. Adequate biofiltration is ALL that is needed. Mechanical and chemical filtration are not only unnecessary, they are almost always counterproductive.

Biofiltration is a complex topic that I'm not even going to dive into here. Fortunately, someone put together a nice video that's both entertaining and informative that simplifies things. Here's the link: