# Expanded clay pellets for biological filtration



## Karen00 (Sep 19, 2016)

Hey folks,

Has anyone used expanded clay pellets/pebbles in their tanks for biological filtration and if so does it work? I'm talking about the type of pellets used for soilless planting in hydroponics, etc. like this https://www.ikea.com/ca/en/p/odla-growing-media-clay-pellets-50288546/.

I couldn't find any posts on this forum but did find a few posts online where people used these and supposedly have had great success with them. They used them in their filters as well as an addition to the substrate. I read they don't break down because of the way they're baked which makes sense if they're used for hydroponics and other such soilless uses. I think the only way they might break down would be in the substrate if plant roots cause them to crack.

I'm curious as to whether this will work for both types of bacteria needed for the ammonia, nitrites and nitrates or whether the pellets just support the ammonia and nitrites (or should they be avoided).

I have a bunch of these left over from some terrestrial container plantings I did a couple years ago and would like to use them for my tank if it works.

Cheers and thanks.

Karen


----------



## Jeepcarpenter (Sep 29, 2018)

They work just as good as the foam sponges, dish scrubbies, lava rock, ceramic and other pourous media.

I used them in aquaponics setups for a few years and did not notice any breakdown aside from when left in freezing conditions if not fully dried.

Auditing costs, I wound up switching to just lava rock as grow media, get mine 40lbs for $11 at HardCo in Whitby and use it in my tanks and filters alike, as well as for grow media.


Sent from my iPhone using Tapatalk


----------



## infolific (Apr 10, 2016)

Karen00 said:


> I'm curious as to whether this will work for both types of bacteria needed for the ammonia, nitrites and nitrates or whether the pellets just support the ammonia and nitrites (or should they be avoided).


Growing the bacteria to process nitrates is more about providing an oxygen-free environment. That's a difficult thing to do in the typical aquarium filter.


----------



## Karen00 (Sep 19, 2016)

Jeepcarpenter said:


> They work just as good as the foam sponges, dish scrubbies, lava rock, ceramic and other pourous media.
> 
> I used them in aquaponics setups for a few years and did not notice any breakdown aside from when left in freezing conditions if not fully dried.
> 
> ...


Thanks for this! I'm glad to know these work and are suitable for an aquarium. I have a lot of this leftover so think I will give it a try. I have read great things about lava rock and the cost of that is unbeatable. Thanks for letting me know where you get it. That was something I was going to look into until I remembered I had all of these leftover clay pebbles.


----------



## tous (Jun 22, 2017)

I have some of these; they are not particularly porus. They are more interesting in the tank imo then useful for filter material.


----------



## Karen00 (Sep 19, 2016)

tous said:


> I have some of these; they are not particularly porus. They are more interesting in the tank imo then useful for filter material.


I took a closer look at the ones I have and I have to agree that they aren't super porous so you're probably right that they would work better in a decorative capacity than biological. I did put some in a media bag to try seeding them but I haven't had to use them yet so have no idea whether they might work for that purpose.


----------

