5 Gallon Filter for Pond

Last summer, I described how to make an "instant pond" with a Rubbermaid stock tank. http://www.kokosgold...6-instant-pond/

Initially, I used the 50 gallon pond as a holding tank for a shubunkin and 3 comets, all about a year old, while I was finishing the pond they would move to. The tank worked great for them. When the new pond was ready, they moved out and were replaced by 4 fancies of the same age. These fish were not really getting an upgrade in water volume, since two of them had been in a 20 gallon and two in a 30 gallon. But since the stock tank is shallow with a huge surface area and a nice fountain for swimming space and aeration, it was an improvement. It was also a lot warmer since the the house ranged from 75 F at night to 80 at midday, while the outside air temperatures ranged from 75 to 95. But whatever the reason, they grew like crazy in the stock tank. By winter, it was clear that this little pond, as set up, wasn't big enough for them. They either needed a bigger tank or improved water handling. Another problem was that Hoover, who is copper-colored in an aquarium, was a "phantom" in the black stock tank -- virtually invisible. I wanted to see him.

So I decided on the following upgrades:

an external filter to replace the submerged bucket filter of the instant pond. A bucket of filter media in the pond with a pump in it will work just fine for handling nitrogen compounds, but it's not very good at mechanical filtration. These guys were turning into real poop machines, so I needed something better.

a trickle-in trickle-out water change system. This is like the automatic water change system I set up for my front pond. http://www.kokosgold...c-water-change/ Koi people have compared the growth and health of fish receiving weekly water changes to those getting the same amount of new water by trickle, and the results were convincing enough that if you go to a koi forum people don't talk about whether they use trickle in-out or conventional water changes, they just compare their trickle systems.

a sand substrate so I could see Hoover and also see debris.

So let's start with the filter. I started with a 5 gallon paint bucket that has been one of my "clean water" buckets for some time. Eventually, I will want to paint it, and old plastic is a lot easier to paint than new.

The first thing I did was put in an exit pipe to dump the filtered water back into the pond. Here's the materials and tools:

I needed from left to right: a drill, a hole saw (which is not a separate tool, but a drill attachment for making a hole), and a uniseal. http://www.aquaticec...es/829/Uniseals There are two uniseals in the picture so you can see both sides. I was using a 1 inch pipe, so I had a one inch uniseal.

I marked where I wanted the hole for the out spout.

Now I screwed this up because I didn't put the hole saw up to the bucket before I marked the location. when I did, I realized both the lip of the bucket and the ridge below the hole were in the way of the saw. If i had noticed this earlier I would have cut off the ridge and moved the hole down a bit. But I didn't so I just cut.

So it looks a little messy. I trimmed off the ridge with a pruner, and filed and sanded the rough rim and the little tags in the hole. Then I pushed the uniseal into the hole.

It seemed loose, and I hadn't used a uniseal before so I was a little worried, but it was fine since the pipe expands the uniseal when it goes in. I didn't put the pipe in until I finished the interior plumbing.

to be continued. I have an appointment.