Buy your pond plants online

Vol:  407 Date:

April 11th 2004  

The Water Gardens Gazette 

1. An important article  .. what really happens in a biofilter

2. Pond plants available on line here

3. Admin section

It is Easter Sunday as I write this Gazette. Why? ... because I am off on holiday for 2 weeks tomorrow and will miss my deadline for later in the week. I am one of those fathers who despite being a bit (OK quite a bit) beyond middle age have a 14 years old son who is passionate about South African wildlife, game reserves and conservation in general. This means we take advantage of the school holidays to take whatever break we can get. So we are off to the Eastern Cape coast close to the exciting Addo Elephant Game Reserve soon to expand its boundaries to incorporate pristine coast line and become "A Big Seven , not just Big Five" game reserve. Want to know what the Big Seven are? .... well my son also owns his own site that is developing nicely and he talks about the Big Seven on it.

This is the web address  .....  http://www.south-african-game-reserves.com ... go on take a look, he would appreciate it

1. What really happens in a biofilter ... I consider this article to be one of the most important I have ever written. Biofiltration Understand the basics well and you will never go wrong.

The Basic Nitrification Cycle

The waste products from the fish in their initial form are mainly expressed as ammonia which is poisonous in even small quantities and especially so under certain water conditions high pH which will be discussed later.

In a mature pond a class of bacteria in the biofilter removes the ammonia almost as soon as it is formed. The ammonia is converted into other nitrogen chemicals called nitrites.

Another type of bacteria also present in the biofilter then converts the nitrite chemicals into nitrate chemicals. These chemicals are less polluting and toxic than either ammonia or nitrites both of which are poisonous.

These chemical processes are occurring all the time and will not stop unless the biofilter system stops working or the source of nitrogen is removed ie no fish in the pond, or the water becomes devoid of oxygen.

The health of the pond is determined by this relentless ongoing conversion of ammonia to nitrates. It must NOT stop for the sake of your fish.

If pond water is changed frequently then to some extent the poison levels are controlled. The more fish in the pond then the more the waste products to get rid of. Koi produce 3 times more waste than goldfish of the same size - because they eat 3 times more.

The food used has a significant impact upon the amount of waste produced. Do not use foods with high ash contents - this indicates low quality raw materials have been used in the food manufacture which result in water pollution levels being higher than necessary

In a natural stream or lake fish concentrations are generally low. Waste products are converted to relatively harmless nitrates by naturally occurring bacteria. Rocks, submerged trees, plant roots, etc all help to purify the waste products from the fish by providing holding points for the bacteria to live on. The more bacteria there are the better the purification.

The bacteria need oxygen to survive and they get this from the water - oxygen is absorbed by the water due to the action of waves, waterfalls and wind.

In a garden pond a biofilter is installed to make up for the unnatural conditions prevailing. A biofilter is designed to allow large concentrations of bacteria to operate effectively in a small volume within a garden pond environment.

Ccorrectly specified and installed biofilters create healthy environments in which fish can live for many years and grow to their full potential.

In small ponds the filter can be installed directly in the pond. For larger ponds the filter needs to be installed outside of the pond. The pump connected to a biofilter must run 24 hours every day otherwise the bacteria will die from lack of oxygen contained in the circulating water. It is a good idea to have a waterfall and a fountain to increase the oxygen content of the water.

It is difficult to add too much oxygen to a pond.

Oonce the bacteria have died it will take approximately 5 more weeks for them to regain close to their previous levels.

What is happening inside a biofilter?

I created this picture below to help explain what happens inside a biofilter.

Imagine the water is flowing from left to right ....

Imagine the red balls are ammonia excreted by the fish. Also imagine water is flowing over the biomedia from left to right.

You can see lots of red ammonia molecules are flowing into the filter although they are dissolved in the water in reality. Look carefully and you will see dark grey Alfagrog biomedia underneath the coloured balls. Look even more carefully and you might see the oxygen bubbles also dissolved in the water.

The ammonia mixed with oxygen in the water is continuously flowing across the biomedia (Alfagrog). The yellow bacteria can be seen sitting on the surface of the biomedia just waiting for ammonia and oxygen to come along.

At the point where the water meets the biomedia (ie where the bacteria live) the red ammonia molecules are broken down (oxidised is the correct term) by the bacteria which keep taking deep breaths of oxygen in order to complete the conversion of ammonia and nitrites to those blue molecules that you see starting to appear. These blue molecules are nitrates. You do not need to be a chemist to understand the next line but do take a moment over the next paragraph .

NH3 is converted by one type of bacteria to become NO2 this is converted by second and different type of bacteria to become NO3. All I want you to take notice of is that ammonia has no oxygen, nitrite has 2 atoms of oxygen and nitrate has 3 atoms of oxygen in its molecule. If the water did not have oxygen in then this conversion could not happen.

Notice the mixture of pretty colours in the middle of the picture this is where the conversion and intermingling action is taking place. You can possibly imagine lots of things are happening at the same time in this region.

The nitrates become the fertiliser for the plants and stay in the water until consumed by plants or pumped out of the pond with a water change.

You will notice that there are still a few red ball bits of ammonia left because the bacteria did not manage to get to them first time around circuit these get eaten next time or maybe even the next.

Just after feeding fish the red balls increase by an enormous amount and as such you will nearly always measure ammonia in the water shortly after feeding. However if the biofilter is mature and working well this is rapidly brought under control.

I have just described in simple terms what is called the nitrification cycle that occurs in all ponds and natural waterways. 

Information on Alfagrog

Without getting too technical this means that 1 litre of Alfagrog can hold the same amount of bacteria as 200 litres of plastic tubes. In other words a box using plastic tubes needs to be 200 times bigger in volume than one containing Alfagrog to get the same biological performance.

Alfagrog fantastic low cost biomedia ... buy here, search for SUPRA after clicking

Alfagrog looks a bit like cinders, it is lightweight, comes in different sizes and you can literally blow through it because it is so porous.

"The Complete Pond Solver" by Tony Roocroft

2004 Edition. Essential reading for anybody who wants or has a garden pond. Get 12 Excel pond calculators free as well as "Water Lilies and Pond Aquatics" ebook also free

Learn More

2. Pond plants for this season

Pond plants ... every garden pond should have some (even those small barrel ponds I discussed last time). Here are some suggestions for this season and where you can get them on line ... click the image banner below and then choose Water Plants once you get to home page

 They have nice basic variety of water lilies for sale ... every pond should have a water lily or two. There is also a wide range of marginals too. Well worth a look Other plants available ... see the pictures at my web site by clicking the link not placed here to reduce download time  

3. Permission To Publish and Admin section

Bona fide web masters and web site owners who have a genuine interest in helping people succeed in pond keeping are welcome to publish articles from these Gazettes subject to one simple condition. Please include in the opening to the article the following link. All you need do is copy these 2 lines of code and paste into your HTML

"http://www.practical-water-gardens.com/"

All you need to know about water gardens, ponds, pumps, bio filters and UV lights

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(c) copyright 2003 - 2004 Tony Roocroft, All rights reserved.

Recommendations Worth A Look

Biofilters between 1,000 galls and 5,000 gallons capacity are claimed (no UV included) with Alfagrog ... 3 different sizes . Shipping was free and I think still is but check

  click here BIOLOGICAL POND FILTER .... 1000 galls

click here BIOLOGICAL POND FILTER .... 3000 galls

click here BIOLOGICAL POND FILTER .... 5000 gals

Biofilters between 1,000 galls and 5,000 gallons capacity are claimed  with Alfagrog and UV included for algae free water 3 different sizes  then click here to read review

MORE REVIEWS BELOW ... don't buy any new pond equipment until you have read these  Pond Professor Price Intelligence Reports

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Looking for large floating pond aerator fountains?

Discover fiberglass rock water fountains

Its called bioaugmentation .. Microbe-Lift bacteria to keep ponds healthy

Go here to select the correct pump for your own pond or waterfall

For any purchase from KRUPPS note following .... | 5% discount at Krupps.com- Just enter Rebate code: cj3579 and you will receive 5% off your next order at Krupps.com

Other Pond Professor's water related web sites created to help others

Water filters for humans not fish

Water softeners for the home

Water heaters for home and recreation