There is no arguing the benefits you get from a DIY trickle style filter coupled with a sump.
Every extra gallon of water you add in a sump further dilutes toxins such as Ammonia and nitrites, and will increase the amount of time necessary between water changes, or simply create a cleaner environment for your pets.
More Filter Power
The DIY trickle filter has the ability to support overstocked tanks more effectively than any hang on back or cartridge style filter available commercially. With real estate measured in square feet and not inches the filter medium can support gigantic bacterial colonies in comparison.
As water trickles through the filter, it’s surface tension is broken maximizing oxygen levels in the water. Since the filter medium is in contact with oxygen, it creates a desirable home for aerobic bacteria to colonize and break down tank waste.
Many aquarium hobbyists soon become board of replacing expensive proprietary filter cartridges. This trickle filter only needs a rinse perhaps every six months to a year and is inexpensive to build and maintain. After the initial investment in “pot scubbies” , there are no pads or cartridges to replace.
One of the few drawbacks of traditional trickle filter systems is the amount of space that they occupy. Traditionally a DIY trickle filter would resemble a chest of drawers with the water trickling from the top drawer to the bottom drawer or sump where it would be returned to the tank. Each level would have various types of media to filter and remove large debris, and then smaller particles, and finally toxins through the aerobic bacteria. In this DIY, having the trickle filter component contained in the large pvc pipe keeps the whole system compact, and minimizes evaporation.
If you are not familiar with my DIY overflow system, now would be a good time to read this article, as this trickle filter uses bits of the overflow.
Parts List. These are the parts that I used. Feel free to experiment with what ever you have lying around. That is the beauty of DIY, everything is customizable!
- 5 1/2 inch Diameter PVC pipe around 4 -5 feet in length
- Large HBH Veggie flake container or comparable food safe container (Ie: yogurt container)
- 1 inch Drain Bulk Head
- 5 1/2 inch Cap for your PVC pipe I prefer black, but the blue one was cheaper and contrasted well in the photos.
- More than enough pot scrubbies to fill the pipe
- Smaller diameter PVC pipe and matching end cap that will be used as the intake for the overflow inside the tank.
- Needle point screen or some other barrier to keep tank inhabitants out of your overflow.
- 10 Gallon or larger aquarium or sump container. Bigger is better. Depending on the room you have available, even a large Rubbermaid tub will work exceptionally well. I chose the 10 gallon because it just barely fit on the bottom of my fish tank stand.
- Return Pump that is strong enough to return the filtered water from the sump tank to the main tank above it. Usually 4-5 feet. In my opinion bigger is also better here. Extra flow can always be adjusted and limited down the road.
First off we’ll setup the parts in mock up, so that we can get our measurements right. Place the PVC pipe in your sump tank and place it directly beside or behind your aquarium setup This pipe should be cut to nearly the height of your tank.
Once you have you PVC pipe cut you are ready to drill some one inch holes around the base. Put the cap on the bottom before you drill the holes just to make sure they are above the cap. It really doesn’t matter what size of hole you drill. Just be sure that they are large enough to ensure good flow, yet small enough that your filter media doesn’t strain through.
Next we create the “jug” portion of the overflow. you need a container that will nest in the top of your PVC tube. I used the container from a popular veggie fish food. It just happened to fit perfectly in the top. I have also used yogurt or sour cream containers saved from the recycling bin successfully. Sometimes its easy to forget the “Reuse” is the second of the 3 R’s of recycling (Reduce, Reuse, Recycle).
What ever you use make sure it won’t fall into the pvc pipe and that it can hold at least 750ml of yougurt, because you will need the depth to control water levels in the overflow.
Install some form of bulk head or stand pipe in the bottom of the container. I used two in in an experiment to reduce the gurgling drain sound. It works quite well so far, but you can use a single drain of at least 3/4 inch.
For bio-media this trickle filter well be using pot “scrubbies” or plastic dish scrubbers commonly found at the dollar store or cleaning aisles. These woven plastic sponges have a huge surface area for bacteria to colonize, and best of all will never have to be replaced,Probably for hundreds of years to come….
Fill around 80% of the PVC tube with pot scrubbies or filter media. You want a filter material that is coarse with a large surface area. I’ve tried using polyester floss to “polish” the water, but found that it clogged the filter too quickly and inhibited the flow of water. I imagine that commercial solutions such as “bio-balls” would work as well.
Insert the container into the loaded PVC tube and stand the pipe in the corner of your sump. In my setup I used a 10 gallon aquarium as a sump for a 55 gallon tank. I usually fill the sump with an indiscriminate amount of pot scrubbies as well. They collect mulm nearly as well as the scrubbies in the trickle filter, helping to clarify the water. Make sure your sump is covered. This will keep the water from evaporating and keep any critters out. I used white Coroplast to fashion this aquarium lid.
Next well cut the smaller diameter pvc tube to length and put a cap on the base. Wrap the needle point screen around the top and zip tie it together. This will keep fish and larger debris out of the overflow.
Place the overflow intake in the aquarium adjacent to the PVC trickle tube. The height of the intake sets the water level in your tank, I find that if i need a little adjustment, I can loosen the bottom cap or tighten it.
Put your vinyl tubes into place in the top of the overflow container. DO NOT CONNECT THEM TO THE BULKHEADS. The vinyl tube should be loose on the bottom. Insert a length of air hose tubing halfway into your vinyl tube and connect the other end to a power head venturi valve.
You are ready to start your overflow. To prime the overflow, pour a cup or two of water into the veggie container so that the water starts to drain down through the bulkhead.
As usual always monitor your DIY project for the first few days/weeks/months to ensure that no domestic disasters can occur. Don’t put more water in the system than you have to. When topping up my tank, I fill it until it is about 3/4 full. This way if the power ever goes out that last little bit of water leaving the tank won’t flood your fish room.
I usually clean out the scrubbies at about the 6 month mark. I’ll dump the scrubbies into a bucket of tank water and stir them around to loosen the majority of the mulm. Make sure that you don’t clean the pot scrubbies too well or you’ll risk upsetting the bacteriological component of the filter.
well seasoned pot scrubbies, and the cleaned ones below.
Hopefully i’ve helped you conceive a new filter of your own. I’ll try to answer all your questions in the comments, I would love to see what you have come up with too, so don’t be shy!
- Rohan Kapoor on 01 Aug 2010 at 3:45 pm #Hi Marcel,
Just bought a 120 gallon fish tank and am trying to build a setup that will be able to support 3 Oscars. Thinking about using a 22 gallon Rubbermaid tote as the filtration box with a 5-1/2 inch PVC pipe pulling water in.
Do you think that this will have enough filtration to support three Oscars? Would a bigger tote be needed for a 120 gallon tank? Would you add two 22 gallon filters for the tank?
- Marcel on 19 Aug 2010 at 9:43 pm #Hello Rohan,
I think the 22 gallon Rubbermaid tub would be fine for your purposes. You have a large tank for three fish, even if they are Oscars, but keep in mind the more water the better in any aquarium system. Let us know how you make out!