Jump to content


Perlite As A Fiter Media?

  • Please log in to reply
9 replies to this topic

#1 Plecc


    Fish Crazy

  • Member
  • 226 posts
  • Gender:Male

Posted 07 May 2012 - 06:36 AM

Hi all,

Just stumbled across a post where another fish keeper is using perlite as his biological filter media.
This appears to be a really good idea! it has a very large surface area and from what i can tell is also inert and dirt cheap :)

wikipedia says - "Perlite is an amorphous volcanic glass, it has high permeability / low water retention.
Perlite is an excellent filter aid. It is used extensively as an alternative to diatomaceous earth. The popularity of perlite usage in this application is growing considerably worldwide. Perlite filters are fairly commonplace in filtering beer before it is bottled".

What do you guys think? any reason not to give it a go?

#2 OldMan47


    Livebearer fanatic

  • Retired Moderator
  • 16890 posts
  • Gender:Male

Posted 08 May 2012 - 01:30 AM

I would be interested to hear about your results. If I recall correctly, perlite has a very low density so you will need to contain it somehow. It should be fairly easy to do that in a typical canister filter though.

#3 Plecc


    Fish Crazy

  • Member
  • 226 posts
  • Gender:Male

Posted 24 May 2012 - 08:56 PM

OK, I decided to give it a go,
so here is a bit of an update!

At the moment the filter is a 7L DIY internal filter powered by a 1000L/h maxijet.
The first stage is coarse then fine foam followed by 2L of bio balls and as the final stage 3L of perlite.

I tried to wash the perlite in a bucket with tap water but unfortunately it was very buoyant, so i mixed it around a bit and then scooped it out with a sieve and rinsed it a bit more under the tap.
I manged to get hold of some fine mesh media bags to keep the perlite in place, and repeated rinsing each bag under the tap for at least 10 min's each to remove any bits that could fit through the mesh of the bag, then loaded the bags into the filter.

Being lazy I dumped the bucket I used for the first bit of the cleaning outside and didn't bother cleaning it until the next day, when I did come to sort it out the fine particles had all settled and formed a thick 1" layer like clay at the bottom of the bucket. I was amazed just how much fine silt and rubbish was removed from the 5L of perlite!
The filter bags now only contain 3mm+ bits of perlite.

shortly after turning the filter on I noticed a very slight cloudiness to the water when looking down the length of the tank, this cleared within 24 hours and left no residue on the sides or bottom of the tank.

A few weeks on, things are looking promising!
The flow rate is still very good, all the perlite is staying where its meant to be and hopefully cleaning should be nice and easy.

I will give it another 3-4 weeks and remove the original cycled filter and see how things go. :)

Edited by Plecc, 25 May 2012 - 04:27 PM.

#4 Aquamaniac


    Fish Crazy

  • Member
  • 357 posts
  • Gender:Male

Posted 24 May 2012 - 09:00 PM

I will certainly follow this one closely. Good media alternatives are always welcome.Besides i do like some DIY myself.



    Fish Crazy

  • Member
  • 353 posts
  • Gender:Male
  • Location:Netherlands
  • Real Name:Jeffrey Lebowski

Posted 24 May 2012 - 09:01 PM

great thread..

Going to try it..

#6 Aquamaniac


    Fish Crazy

  • Member
  • 357 posts
  • Gender:Male

Posted 24 May 2012 - 09:01 PM

I will certainly follow this one closely. Good media alternatives are always welcome.Besides i do like some DIY myself.

#7 Dazzler666


    Fish Crazy

  • Member
  • 389 posts
  • Gender:Male

Posted 24 May 2012 - 10:10 PM

Likewise!! I'm getting a 5ft tank with two external filters which require new media do may we give this a go! 😜.
Great thread .... Bonus! 😊

#8 Plecc


    Fish Crazy

  • Member
  • 226 posts
  • Gender:Male

Posted 25 May 2012 - 04:25 PM


I will do my best to keep it up to date!

I forgot to mention I have a 1" thick layer of medium density foam just after the perlite, the very final stage before the water exits the filter.
Just to help distribute the flow and act as a screen to prevent any loose perlite making its way into the tank.

Be careful if you want to run perlite in a canister filter!
The powerhead on my DIY filter picks the water up from the bottom of the tank and pushes it through the media, so there is no risk of any loose perlite making it's way into the impeller.
On my Fluval canisters the pump is the final stage of the filter, sucking the water through the media.
So any bits of perlite that get loose could be pulled into the impeller.
I'm not sure if this is the same for most canister filters.
But if you add a nice thick fine foam screen just before the pump things should be fine :)

#9 RCA


    Fish Herder

  • Member
  • Pip
  • 1515 posts
  • Gender:Not Telling
  • Location:United Kingdom

Posted 27 April 2013 - 09:51 AM

Just viewed a video discussing using Perlite as a filter medium.  Thought I would check TFF before starting a new topic, and lo and behold here is such a discussion.


I found this useful in describing Perlite and its general uses.


Anyone had any personal experience with this product, either with their fish or even in the garden?


Plecc still appears to be active, therefore maybe he can provide an update of how this worked out in the long run for him?  I will send him a PM to prompt him ;)

#10 Plecc


    Fish Crazy

  • Member
  • 226 posts
  • Gender:Male

Posted 02 May 2013 - 06:46 PM


All in all I found perlite to be great!

I ran that filter for around eight months with no issues whatsoever,

The only reason I am not still using it, is because the new external came packed full of biological media and I needed to run them both at the same time when swapping them over.

So yep perlite gets a big thumbs up from me. :)

And considering it costs a few quid for around 10L +++


But be WARNED!


It is unbelievable how much rubbish you need to remove from it!

first wash in a bucket replacing the water a few times, this will remove all the fine dust and sandy particles.

Scoop it out with a sieve (something close to a 1mm squared mesh)

And run under the tap for 5-10 minutes.

I cant remember for sure, but I think I then put it in boiling water for a few mins to sterilise it. but not 100% on that one.

after cooling I put it in FINE media bags, make sure you wrap the cord around the end and tie it off.  And then spent  probably 15-20 mins in a bucket of water and then under the tap trying to remove any bits that could make it through the mesh of the bags.

It's is definitely not the easiest stuff to work with as it floats and gets stuck all over your hands!

Also if perlite was to get pulled into your pump, both the housing and impeller could get very badly damaged!

Sorry to repeat myself a bit, but I don't want to cause anyone any problems.

But besides the tiresome initial cleaning, once all set up it is so easy to live with.

When cleaning the filter, just pull the bags out, give them a quick shake in a bucket of aquarium water, job done!


Once matured it kept the tank water extremely clear and polished, a noticeable improvement on my other tanks.

Which contained 3 stage foam, ceramic rings and Seachem Matrix.


0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users