Wednesday, September 28, 2005

Improvements on a Skippy Fish Pond Bio-Filter

I like the whole idea behind the Skippy design......

A Skippy bio-filter, built using a "Rubbermaid" water tank. Note the large flange outlet.
A Skippy Bio-Filter

However I had some ideas of my own to make it more efficient:-

  • My pond is not massive (about 400 gallons), so I didn't think I needed a tank as large (or ugly) as a "Rubbermaid" used for the Skippy filter. Please remember that I am not a professional Koi-keeper! I have koi, but not that many and they are mixed with other smaller species of fish. So I don't need a massive filtration system, I just want to improve the water quality and eliminate green water from my small pond the same as many fellow ponders may do.
  • Generally a Skippy filter is situated at the top of, and is effectively part of a waterfall, with its large flange outlet, the water literally flows out and down the waterfall (with rubber sheeting around the flange to prevent water leaking behind any rocks which form the waterfall). To accomodate this size of tank into my already built rockery simply was not practical, and I wanted a design with flexible pipe to put the water where I wanted it - in the back of my terracotta urn.
  • I particularly liked their "vortex" design, where the pipework creates a swirling motion in the base of the filter, but a "Rubbermaid" is oblong. Using a cylindrical tank would be better to maintain a smooth swirl in the bottom.
  • I wondered whether I might find something that looks nicer, and could "blend" into the garden better.
  • Rather than having a drain outlet in the side, I thought that a drain exiting vertically down out of the base would help remove filtered solids more efficiently. A Rubbermaid tank has a small outlet in the side, near the base, which is fine for draining just water, but not great for getting gunky muck out of a bio-filter!
  • After reading up on "venturis", I wondered whether a venturi dedicated to aerating the filter would improve oxygenation of the aerobic bacteria in the bio-filter.
So there you have it. These were my criteria and ideas for building my own design based upon the Skippy bio-filter.

To see what I did, visit my web site.

Tuesday, September 27, 2005

Online Pond & Fish-Keeping Forums


For great fish-keeping communities visit my favourite pond and fish-keeping forums at:-

They are very friendly and knowledgeable groups of people who will make you feel very welcome.

There is always tons of discussion going on about fish of all kinds, problems whether relating to the health of your fish or the state of your pond, and advice on pond bio-filters, pond liner, fish pond pumps and anything else you can think of!

People regularly post pictures of their own personal pond building projects too, and there is a great variety in their size and style, making a fascinating read.

Friday, September 23, 2005

A Skippy Bio-Filter

Before going any further into my bio-filter project I would like to show you a web site which I thought was a breath of fresh air amongst all the technological gobbledy-gook being pushed at me by the myriad of web sites whose sole purpose appears to be providing "good advice" with the ultimate aim being that you buy one of the multitude of different makes of pumps, filters and other accessories.

If you have been doing some research on the Internet on ponds and filters, you may have come across a web site called Skippy's.

Skippy's is the site that gave me the inspiration to have a go at building my own BIO-filter. And the most wonderful thing is it explains all about "freakin magic"!! You NEED to know about Freakin Magic in order to understand ponds (you'll see what I mean if you don't already know), in fact you'll learn about Nature and LIFE! In fact even for experienced pond keepers, it makes a great read - the emphasis is on helping you understand how to work with Nature to create balance, not against her.

Skippy's then tell you how to build your own DIY vortex/settlement-chamber based BIO-filter. Its a great site but for one thing. I don't think they make it clear enough that you need to PRE-filter the water going into the BIO-filter (maybe I missed something!). For a novice like me I got the impression their bio-filter was able to do everything. It wasn't until after I had built my basic bio-filter based upon their ideas, and then later read in their associated forum about other newbies who similarly misunderstood the need for PRE-filtering, that I made some changes. (I also emailed them about it and they confirmed I was right).

Anyway, my Leisure web site details my own take on the Skippy Bio-Filter. Once you've read their web site (and I strongly recommend you do), if you are interested come back and see how I've done it (and how I implemented a simple venturi too - a mechanism to mix air into the water with no moving parts), and also where to get media for your Skippy filter if you're in the UK (Skippys is a USA site).

So here it is ...... Skippy's bio-filter - I suggest you start first by reading this page, closely followed by this page to learn about Freakin Magic, then go to this page for their Bio-Filter construction.

To learn more click here for my bio-filter design web site.

Green Water Problems

Green Pea-soup

During the second year in our pond our fish had babies, and the adults were growing at an amazing pace. We started with 12 fish, a mix of goldfish, shebunkins, and ghost-koi, all of which were about 3 inches or smaller. Now the ghost-koi look fantastic and the biggest is about 12 inches long and looks very stocky and chunky. I'm sure he'd make a good dinner (only joking).

For the first year the water was lovely and clear, even in the summer, and we had good cover to provide shade from the marginals, like lilies, water hyacinth, and "Fairy Moss" - that red-leafed surface cover weed that can take over the pond and you end up scooping out handfuls of the stuff. Also in the boggy area of our stream we had a good variety of bog-plants; Marsh Marigold, Horsetail Rush, Water Musk.

The main pond, now covered with netting since we lost 2 beautiful carp to a heron.

But, in the second year (Summer 2004) things suddenly started going wrong.

Three things seem to be the culprit:-

  1. The fish were much bigger, and eating more, were therefore excreting more.
  2. Even though we put more of the Fairy Moss in the pond to get more cover to keep out the sun, it didn't survive, we think the fish were eating it(?).
  3. The yellow-flowered Water Musk had pretty much taken over the entire bog-area, and so we had a mad fit and removed ALL of it!

Ooops! Within about 2 weeks the water went a pea-green, taken over by fine water-born algae. We couldn't see below about 4 inches, any deeper and the fish could only be made out as dark shapes passing below.

In hindsight we now realise that the plants in the bog-area, with their massive root network, were acting as a wonderful natural "veggy-filter" to eat up nitrates in the water, hold back any crap being pumped out of the pond coming back down the stream, and provide a home for bacteria that was helping the whole "balance" process.

When we designed our pond, waterfall, stream and bog-area, we didn't really appreciate what a clever design we had given "nature" to work with.

And we had just messed up big time by removing the most vital part of the cycle. A natural vegetable biological filter.

Initially we didn't figure out why it had happened. At about the same time the fish had been traumatised by the heron eating two of the larger fish, and we thought the water was cloudy because they were stirring up the bottom silt to "hide themselves".

I was also starting to get very fed up with cleaning my Bio-Force filter literally every 2 to 3 days, and having to remove the Cascade water pump from the pond every week because that too was getting clogged up, mostly by blanket weed.

I knew that sunlight was going to be a major cause of the algal-bloom, but I was starting to get concerned about the state of the water and the health of the fish, the water at times was almost looking "black", and so started my quest to learn more about what was going wrong and how to resolve the problem.

Building a Small Stream to lead into your Pond

One of things that really makes a big difference to the enjoyment of our pond is the little stream and bog area. I have added some more information about this, and so have created a new page on its own. Click here to learn how to build a stream leading into your pond.

It's well worth the effort. A stream and bog area attracts so much wildlife; we get frogs, dragonflies, water-boatmen. Also its a delight to see wagtails and blackbirds come to wash in the stream. On or two occasions when heavy rain has raised the water level in the pond to overflowing, the smaller fish will swim up the stream to explore.

Safety and Disclaimer

Disclaimer: I am not a professional, and my small pond is not specifically for Koi fish, this project is purely suggestions from my own experience and research. Some aspects involve modifications to equipment that could invalidate your warranty. I just enjoy trying things out, and judging by the number of people looking for similar information in fish pond forums, as one of them you might be interested in my ideas.

Safety: Please be careful! If you have a young family, do remember that kids are fascinated by water. You really should think twice about building a pond if you are unable to supervise youngsters at all times. Tiny tots are fearless and don't understand the dangers of water, and it only takes a minute for a little person to drown, even in very shallow water. Having said that, our grand-children visit regularly, and with constant reminders they learn to be careful. But we never let the youngest ones near the pond without an adult right by their side.

Sunday, September 18, 2005

Welcome At Long Last

Hi friends and welcome at long last to my long overdue blog!

This is something I have been meaning to do for quite a long time to record my ideas, designs, experiments and progress on my alternative Skippy-style bio-filter.

My Pond

So folks, this goes out specially to all you pond and fish enthusiasts who generally have small ponds, don't have much cash to spare, or just want to learn how to improve the health and clarity of your water, and so keep happy fishes!

A more recent photo showing plants established but even this has been improved on.

I first started my Leisure web site about a year ago to show how I designed and built my own homemade bio-filter when I started to get terrible green water (thick green pea soup) in my pond due to water-borne algae.

After much research getting ideas from various fish pond web sites and forums I got an idea for creating a design that was a more attractive than most homemade bio-filters which are often constructed using a "Rubbermaid" tank - a big hulking water tank with appropriate plumbing, usually sat at the top of a waterfall, and which normally requires hiding behind plants, rocks and the like because it is so big and ugly......

A typical Skippy bio-filter

My pond, like many amateur pond-owners, is quite small at about 400 gallons capacity, and so does not require massive filtration. So I set about building something that looked ok, and incorporated a number of different features to aid easy cleaning, and ensure efficient breakdown and filtration of waste products produced by my fish. For example a vortex settlement chamber, a pre-filter and oxygenating venturi, and more recently a trickle-tower filter.

My first design 2 years ago

Since then I have updated my pond filtration setup in a number of different ways, and recorded these changes in my Pond Bio-Filter web site, but what was lacking was a way of sharing my new ideas, successes and failures along the way.

So this Blog will hopefully act as a way of filling the gaps, and keeping you informed of how things progress.

It made sense to do this because I get a lot of interest in my web site, and various people from around the world have adopted my design ideas and emailed me to ask questions.

I hope you find it useful.

Please just follow the links to my web site, or click here for my web site on How to Build a DIY Pond Bio-Filter, and Homemade Pond Venturis where you will find loads more detail on making this stuff :o)

Good luck.