I got tired of paying a whole-lotta-cash for my Cascade 80 fish filters that I was having to replace every couple of weeks. So I decided to make my own, using furnace vent covers, activated charcoal and and an old filter. I would imagine that this would work for any filter that is a charcoal/batting material. It's been a couple of months and my fish isn't dead yet, but don't hate me if yours dies.


Step 1: Step one!

Alright, so you'll need 3 things:

- Activated Charcoal
- Old Cascade 80 fish filter - I would imagine that this would work with any other type of cartridge filter
- Vent filters - these are used to cover your furnace vents it your house. I would image that a sewing store would have some similar type of material
<p>Wouldn't nylons work just as well &amp; forget the filter stuff?</p>
<p>Potentially... I don't know how fast they would &quot;gum&quot; up compared to the furnace filter since the nylons are finer - you'll have to let us know how the experiement goes! </p>
Will definitely do that. It's day two and so far so good.
i like your koi but the tank looks cloudy
agree. I have a small tank with 2 goldfish and the water is crystal clear. Why? because my filter has a turnover rate of 800 liters per hour, yet i have only 15 gallons.......
that tank looks too small for a koi, how many gallons???
Actually charcoal is usually worthless in a tank unless you are helping to remove medications or dyes, or your tank has a weird smell. other than that like I said Charcoal is worthless
your filter is backwards. filtration process works in this sequence:<br/>mechanical(filter pad) then chemical(activated carbon). Also, biological [beneficial bacteria] is occurring before, during, and after.<br/><br/>&quot;poly-fill&quot; is the best bang for the buck filter material (less than $2=1lb bag walmart, found at most craft/fabric stores), use your plastic screen from old filter cartridge to keep poly-fill from entering tank. Also, get a small fabric mesh bag (pet or craft store) and put your activated carbon in it. place in filter 'after' the ploy-fill and smile =D. you just stretched alota dough.<br/>hope that helps<br/><br/>ps: your koi will be alot happier and live longer in a larger tank with more filtration, more hiding places, and some compatible friends.<br/>happy fishkeeping ~&gt;&lt;=&gt;'<br/>
He was only kept in this tank for a short time as I was between living spaces. He's now much happier with a 20 gallon tank and spaces to explore. Thank you for your concern!
I used the wet dry vac filters sleeves and sewed around the edges for my wisper 2 cartridge filter for over 20 years. If you make sure all the carbon is out you can scrub them quite well, also you can use the vent filter as a insert for better filtration. I have saved thousands over the last 20 year in taking care of 2 55gal tanks as well as other peoples tanks. 20 years and still counting
Do u think felt fabric, might possibly work as well? Im just curious, b/c that is what i currently have at hand. :D
Yes it probably would, I would just watch to make sure that it doesn't kill the flow of the filter. :)
I don't see how such a large fish stays alive in such a large unkempt tank.
You could save even more money in the long run by replacing the carbon with something useful like sponge and only rinsing it in old tank water when it requires it. On a tank so small and with such a large bioload, you need all the filtration you can get...
The sponge is good stuff, it may restrict the water flow too much if you got a really dense one. You need the carbon however - e-aquariums.com states: "Activated carbon or charcoal is a common substance for this purpose. It can absorb chemicals found in fish waste and hold them until the carbon is removed. The carbon has a finite lifespan and should be replaced regularly. Activated carbon can also absorb other chemicals in the aquarium such as chlorine and heavy metals."
No, you don't need the carbon. It's another way for the big companies to part you with your cash. The biological filter, the most important aspect, lives in filter sponges, ceramic media and similar- the bacteria convery ammonia to nitrite, and nitrite to nitrate, which is then removed by water changes. Using a dechlorinator will remove chlorine, chloramine and heavy metals from the water, and water changes will remove other things in the water. Carbon has done all its adsorbing in the first 24 hours or so, after that it's near enough useless as the surface begins to get covered in bacteria and particulate waste.
DARN YOU DARN YOU TO HECK lol :) you beat me to it I guess I will have to go for phase two of my contest winning plan Mwahahahaha! *runs to workshop*
SORRY! :) You had the exact same idea?? Would you change anything? ~Thom
lol its fine I Have another plan that will work :) I like your fish <><
Nice job! I like your fishy. :-) Great Instructable, I like it, I might post one about fishes too.
Thanks! Post away!
good idea. i hate buying new filters every month. i have 3 tanks too so this'll save me some money.

About This Instructable


18 favorites


More by trainwiththom: Computer Cord Tamer - Monitor Style How to make a cheap Cascade 80 fish filter for your fishy friends
Add instructable to: