My New Koi Pond:

Time to finally do a post on building My new Koi pond…

As you may have gathered from this website and a bit of an insight into our lives here at Proanglerkayak.Fishing.

WE LOVE FISH (not all but most “sorry bream”).

So, as I rent my house.

Having a pond is a bit of an issue, as we have moved regularly in the past.

For years I have been restricted in what I can keep and how many fish I can have due to pond restraints.

For instance, I had a few Koi in a very very large GRP water storage tank.

But this was far from ideal for both me and my Koi.

GRP tank
Nexus 320 and Bakki shower

My New Koi Pond

I had been searching for an answer for a long time with no real answer.

Would solve all of the issues above??

Finally whilst doing the usual searches on eBay. I came across a very peculiar item and decided id take a chance and buy it.

It was a steel-framed tank, with a steel base.

With glass windows on all sides (12 in total).
3 panes either side on the longest sides.
Two panes in the ends.

These windows are 1.2-meter square panes of glass.

That are actually 2 sheets of 25mm glass sandwiched together making just over 50mm thick.

Tank on my drive way

Above is a picture halfway through the restoration as I forgot to take any of when we brought it home.

When we went to collect the tank.

The guy we brought it from, said: “it had been build and used in the making of one of the James Bond films”??

My New Koi Pond:??

At Warner Brother Studios.

He said, when this tank was built it was one of two”.

His brother had the other in his garden with fish in it??

I took this with a pinch of salt as anyone would.

As the asking price was more than reasonable and I was happy.

I decided to take a gamble…

It would do the job I needed, We loaded it on to a flatbed car trailer and towed it home.

Once home we used an “A-FRAME” with two 1 tonne chain blocks. Lifting it up off the trailer, whilst we pulled the trailer out and put down a pile of railway sleepers. These being a good strong base for it to sit on whilst I worked on it.

When we got it home…

I had a good chance to look at what we had actually brought, I found there was far more work than I first thought.

Not too much that it would take forever to get up and running but enough none the less.

My New Koi Pond::

To start off the original paint had gone long ago and it was rusty as f$%k. When it was fabricated the base had been filled with about 2 inches of tar and tonnes of gravel, which at the time probably looked great and kept the base in great condition but I needed to remove it to make sure the fish would be safe. All the sealant around the windows had fallen off and every pain of glass leaked like a sieve.

None of this was a big surprise really, to be honest. But you never really know what you’re getting into when you start one of these projects.

Tank on drive

Removing Tar:

I decided to start, by scraping off the 2 inches of tar and gravel from the bottom of the tank. This was a pain to, say the least. When it was cold it wouldn’t come off, in the sun it melted and made a mess everywhere. I ended up having to do this early morning and late evening, so the tar and gravel was just the right consistency that it would come off as easily as possible without smearing everywhere.

This took about 6 days to complete, once done to a good standard I was very impressed with how well it had preserved the bottom of the tank. The base is made of welded 3mm steel sheets welded together and it still looked like new.

Then tackled the rust which was a horrible job. I ended up very carefully using an air chisel to smash off all the thick rust without damaging the glass.

Next was the job of removing all the old sealant from around the glass panels and getting ready for a coat of fish safe paint.

I thought long and hard about how I wanted the end pond to look and wanted to plumb the entire pond in properly without pumps or pipes inside of the tank coming over the sides.

After much thought, I went for a single aerated bottom drain in the corner with a custom-fitted skimmer.

So I order the parts needed and marked the hole in the base for the bottom drain and cut it out. I did not want to fit the skimmer through the glass so I decided to take out one of the panels and weld in a steel sheet so drilling hole would be far easier. Also, this meant in the future I would have a nice panel to add any extra feature if needed.

Removing Glass:

We removed the panel and welded in a new one and I set about painting the inside of the tank.

Comprehensive research was conducted before purchasing any paint as it is very expensive and wanted it done right the first time.

After a long conversation with a very knowledgable gentleman on the phone, I decided to use AQUAKOTE paint. See below link to there site. Their knowledge and help were second to none and I would recommend them to anyone.

I decided to go with black paint to give a nice dark background against all the glass. I painted the inside of the tank first including extra coats around the cutouts for the skimmer and the bottom drain.

Bottom drain and skimmer fitted

My new Koi pond

Next was to address the outside so more rust removal and sanding were needed. Then a few coats of Aquakote paint including the underside. Even though the outside could have painted in something far cheaper like Hammerite, I did not want there to be any issues where the two different paints “from the inside” and ” the outside” would meet. So I decided to just paint the whole tank in the same black Aquakote paint.

Once this was all dry I decided I want to strengthen the top “just in case” as some material and a little strength had been lost to rust over the years. I cut and welded 10mm steel flat bars into a square and dropped it on top of the pond edge with a good coating of fish safe sealant in between them and then drilled and bolted the new top-down with M12 stainless button head bolts.

New pond top “ring” painted and dry

Sealing = crap job

I then had the “crap” job of sealing around the new top and all the panes of glass. I absolutely hate silicone at the best of times especially as I had to try and do a good job of this.

Due to the amounts needed to seal just the windows of the tank, it would take over 100 tubes of fish safe silicone.

I used CT1 for this even though it is very expensive, it is the best silicone on the market there is nothing it won’t stick or seal.

By the end of the build, I estimate we used around 120 tubes of black or clear CT1 to complete and fully seal the tank.

Building the pond base

I then called in some help and got on with the base. I wanted a “surround” made of railway sleepers, so we picked up some sleepers and bolted them all together to make a frame. Then filled the inside with a layer of type 1 and then poured concrete to make a solid base for the pond to sit on.

My new Koi pond

once this was completed and I had to arrange to get the pond into the garden. I called in the help of my old man and his boss to lift it over the roof using there 75tonne hi-ab. They are a very professional mechanical engineering company based in Suffolk called M&C Engineering Ltd. They undertake all sorts of civil and mechanical works. basically, if you want something done they will find a way of doing it. If anyone is interested in their services click the button below.

The Big lift:

With the date arranged for the “big lift,” I cleared the garden and driveway and eagerly waited for the hi-ab to arrive.

Setting up the hi-ab
Lifting the tank
Over it goes nearly there
Nearly there!
Tank in its final positing

My new Koi pond

Once the tank was in place, I set about finishing the painting checking the sealant. Then getting on with the pipework.

So for my filter setup, I went with:

A nexus 320 fed via bottom drain to 80watt stainless UV filter up to a 3 tier Bakki shower using a 20,000ltr variable speed pump

An evolution aqua easy pod via the 3″ skimmer in the wall via the easy pod 18watt UV using a 10,000ltr variable speed pump.

Next, I built a stand for the nexus 320 and the Bakki shower and fitted these, I then added a pad for the easy pod to sit on.

Note: I wanted the pond to have an auto top-up.

I added a stainless bracket I knocked up and a toilet ball valve set, to the correct level for the pond when full.

This is piped in via an evolution aqua de-chlorinator.

Next was to fill up the pond for the first time…

Pictured above:

My new Koi pond:

After careful thought I decided to put a net around the edge of the pond, to make sure none of the fish jump out.

Struggling to get the flow I wanted through the nexus with the standard k1 micro drum inserted. As I will have a lot of fish I needed maximum filtration to keep them happy in their new home.

So I decided to fit a Draco Drum Origin into the top of the Nexus 320 filter
. To keep the water crystal clear and clean at all times.

This will keep everything clean all the time, which allowed me to up the flow.

I couldn’t have done otherwise as the k1 micro clogs up ways to often.

Lastly, I added the fish. A few at a time over the next few weeks and fit the rest of the nets.

Fitting some led lights above the tank for the summer nights. Sitting outside with a cold beverage, and cleaning in the winter.

That’s about it, to be honest

It did not come without issues or problems but was easier than I thought at first.

Feel free to email any time with any questions or if I can help anyone with there pond build thanks.



Happy Koi in the new home.

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