The purpose of the bucket filter is to filter physical particles out of the water as it exits the fish tank. I am using this in my Friendly Aquaponics Micro System 64, IBC fish tank.
The filter that I have presently is too small an area and too fine so it becomes clogged quickly, like every 2 days. The intent is to build a filter that filters the water well, but does not need to be cleaned as often. The hope is filter cleaning will be extended to about 10 days. Mechanical filters must be cleaned often. Biological filters digest the fish and fish food waste that come into them and need very little cleaning or maintenance.
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I was instructed to use screen wire over a PVC pipe as a filter on the fish tank and trap the particles in the fish tank water as it exits the fish tank. They said that I don’t need a mechanical filter, and the air bubbler and activity from the fish would help dissolve the fish poo solids. That didn’t happen. I was careful to feed the fish no more food than they would eat in 0:30 minutes. I used floating food so that I could confirm that all was eaten.
Perhaps the 69 days this summer of over 100 degree temperatures (new record), affected the physical particle accumulations in the fish tank.
Recommendations from other APers locally confirmed I’d need a physical filter. I understood I could build a filter to physically filter the water and it also be a biological filter, but I am staying with the grow bed troughs to do the biological filtering function. Because the fish tank solids were so prevalent, I made a mechanical filter that is easy to construct and service, and inexpensive to build.
The filter connects to the 2” PVC drain outlet on the inside of my 250 gallon IBC fish tank. This fitting is a bulkhead connector through the side of the tank with a PVC slip / glue fitting. This allows easy connecting or removing the fish tank filter for cleaning. The bucket filter mounts horizontally in the fish tank. The filter outlet slips into the 2” PVC bulkhead fitting on the fish tank and the bucket handle is tied to the cross bar in the fish tank for support.
The filter is light weight and allows about 5 times the area for filtration as the original filter I had constructed. Plus the graduation of filter element sizes captures a lot more stuff from the water. I’m using what the filter captures as fertilizer on my potted plants.
- Gravity feed mechanical filter
- Constructed of 6, five gallon buckets, screen wire, and filter material
- All inert material, plastic, poly, etc.
- Easy installation and removal
- Easy cleaning, lid snaps off, pieces nest, just wash with a hose
- Could be used with 3 types of Matala filter material for a little bio filtering
- Replace lid and install PVC bulkhead pipe fitting, to use filter as a pressured / inline filter.
The filter is constructed by nesting five each, five gallon bucket bottoms into one five gallon bucket (the sixth bucket). It is sealed with a snap on lid.
The picture above shows how the buckets “nest” to form a tight seal between them with a space between their bottoms. I use this method to make chambers that filter the water as it passes through each stage of the filter. Each bucket chamber presents a finer mesh filter medium
- I start with a large baffle to trap large solids
- Next a 1/4” mesh plastic screen
- Then an 1/8” mesh plastic screen
- Then a 1/16” mesh plastic screen
- Then 3 layers of synthetic filter HVAC material, ½” thick, cut to fit the round bucket bottom.
(Note: Bucket bottom 5 and 6 in picture were modified, see pictures below)
Number 1 is the main bucket and the housing for all the other parts. Number 7 is the lid that fits on bucket 1.
Notice the index mark on the buckets. This helps align the holes in the bottom of the bucket to maximize flow. Also, it helps align the finger holes that are in the top side edge of the buckets, at 90 degrees to the left and right of the index mark.
Filter bucket number 2 supports the filter material and holds it away from the drain bulkhead.
The filter material is inserted into the bottom of bucket number 2.
Bucket number 3 goes in over the filter material and holds (sandwiches) the filter material tightly in the bucket filter to support them.
Bucket number 4 has a plastic 1/16” mesh plastic screen hot glued to the bottom of the bucket. I chose to wrap the screen around a piece of orange plastic, cut from a bucket lid. It was cut and drilled to match the bucket bottom. This let me hold the fine mesh tighter when hot glued. This piece was then hot glued into the bottom of bucket number 4.
Bucket number 5 has a plastic 1/8” mesh plastic screen hot glued to the bottom of the bucket. Notice in the picture that I had to use two pieces, thus the darker line seen as a slight arc in the picture. The only 1/8″ plastic screen I could easily find was sold as gutter, soffet, roof vent varmint prevention, and was about 9 inches wide.
Bucket number 6 has a plastic 1/4” mesh plastic screen hot glued to the bottom of the bucket.
Number 7 is the lid that fits onto the main bucket, number 1.
The bottom view of the bucket filter.
The bulk head connector used in the filter in the bottom of bucket number 1.
This could have been a uni-seal to save costs, but then you would of had to glue rings of PVC on outside of it, to prevent it from pushing further into the filter. A Uni-seal lets you shove pipe into it, and holds from it coming back out.
Instructions for constructing the filter
- Gather the parts
- Orient all the buckets the same way, and put an index mark at the bottom edge of all the buckets in the same place. Ex: at the bottom center of the logo on the front of the buckets. This will be used to orient all the pieces of the filter as you build and later reassemble it.
- Label one bucket number 1
- Label another bucket number 2 and cut it off just below the lowest “collar” on the bucket. This should allow it to fit into the outer, main bucket and still allow enough room for the lid to fit properly onto the main bucket, i.e. bucket number 1
- On the bottom of bucket number 2;
- Mark 5 equally spaced marks around the edge of the bucket.
- Make the center line of the first hole line up with the index mark on the bucket.
- Draw lines from these marks to the center of the bottom of the bucket.
- Mark a circle an inch just inside the bottom of the bucket.
- Now locate and mark where to drill the center of the 5 three inch holes in the bottom of the bucket.
- Use the outside circle to position the outside of the hole saw.
- Locate and drill two one inch finger holes. One should be about 1 inch from the top of the bucket (end you just cut off) on the left and another directly across from it on the right side. It is best if you align these finger holes at 90 degrees from the index mark. You can see in the picture that I did not do this very accurately, oops. At least my top, first hole is aligned with the index mark.
- Bucket height:
- Align the index mark on 4 buckets and nest them into bucket number 2. Press them down firmly but take care not to jam them together. You just want them to fit tight. These will be buckets number 3 through number 6.
- Cut off buckets number 3 through number 6 to the same height at the bucket number 2, Bucket number 2 is the bucket that you have the other 4 buckets inserted into.
- Drill a 1” finger hole through thru all four of the buckets on both sides; i.e. bucket number 3 through bucket number 6. Use the holes you previously drilled in bucket number 2 as a guide where to drill. Remember, you are doing this while the buckets 2-6 are nested and all their index marks are aligned.
- When completed, the index, holes and finger holes should all align, and the top edge of all the buckets are flush.
- Drill the holes in the bottom of bucket number 3-6:
- Use bucket number two to, mark where to drill the 5 holes in the bottom of bucket number 3, 4, 5, and 6.
- Place bucket number 2 over bucket number 3.
- Take care to align the index marks. When the buckets are nested inside each other and the index marks aligned, the 5 holes should be aligned as well.
- Mark the position for the holes on the bottom of bucket number 3 by using a sharpie and tracing the holes you previously drilled in bucket number 2.
- Now, using bucket number 2 for a template, repeat the above process for locating and drilling the five holes for buckets number 4, 5, and 6.
- Take care to align the index marks.
- When the buckets are nested inside each other and the index marks aligned, the 5 holes should be aligned as well.
- Screen: Cut out a circle to fit the bottom of a bucket from the 1/16″, ¼” and 1/8” plastic screen.
- Hot glue a piece of 1/16” mesh plastic screen into the bottom of bucket number 4. I used the cut out from the center of an orange lid with 5 each 2” holes to wrap and glue the screen around. Then I hot glued it and the screen into the bottom of the bucket to make the screen mechanically stronger.
- Hot glue a piece of 1/8” mesh plastic screen into the bottom of bucket number 5.
- Hot glue a piece of 1/4” mesh plastic screen into the bottom of bucket number 6 .
- Drill one hole in the bottom of the main bucket, bucket number 1, that aligns with the hole by the index mark of the other buckets. Use a hole saw that will hold your bulk head connector firmly.
- Install the bulkhead connector.
- Cut a short piece of 2” PVC pipe and insert into the bulkhead connector, to allow the filter to slip fit into the bulkhead connector on your fish tank. You can use other size bulkheads and PVC as works best for your application.
- Assemble the buckets and lid.
- The bucket filter is ready to be mounted in your fish tank drain.
To install the filter in your fish tank.
Immerse the filter so it will fill up with water.
Mount the drain of your filter into the drain of your fish tank.
It is assumed that your filter bulk head connector will connect to the drain in your fish tank. I use a 2″ bulk head in my filter and in my fish tank. Both are slip PVC connections and connect using a short piece of 2″ PVC pipe.
Support the intake end of the filter by tying the filter bucket handle to one of the cross bars in the IBC fish tank.
You can use rope or a tie wrap. I chose to build a quick connect for the filter handle using three pieces of 3/4″ PVC pipe and some long #10 bolts, nuts, and aircraft (locking) nuts. I just slide it onto the bucket handle and over the cross bars in the IBC fish tank.
The filter is easy to clean.
- Remove filter from fish tank, and insert a temporary filter in its place.
- Drain the water from the bulkhead connector by holding the filter by the bucket handle over the fish tank.
- Put the filter on the grass and remove the lid.
- Remove the nested pieces and filter material and wash them.
- Reassemble the filter in the opposite order that you disassemble it.
- Replace the lid
- Re install the filter into the fish tank.
6 Home Depot 5 gallon buckets $21.00
Two bucket lids, one easy on off (black), one (orange) $5.00
Synthetic HVAC filter material, cut to fit $6.00
¼” grid spacing, plastic screen wire, 12” x 12” minimum $1.00
1/8” grid spacing, plastic screen wire, 12” x 12” minimum $1.00
1/16” grid spacing, plastic screen wire, 12” x 12” minimum $1.00
Hot glue $1.00
One 2” bulk head PVC fitting, screws onto bucket $12.00
Estimated cost of materials (wo tool cost) $51.00
One 3” hole saw
One 1” hole saw
Hot glue gun
Hand drill motor
Reciprocating saw and 6” long minimum, fine tooth blade
Sharpie marking pen, black
Power sander and fine grit sandpaper
Sand paper, for hand sanding
Friendly Aquaponics, Filters for Pumps, Newsletter #80
Feel free to share my idea, pictures, etc. I would appreciate you giving me credit and a link to this article if you use it. Bob Jordan