Pond bio filter bacteria is vital

Using bacteria in your pond

Three very important things when you have finished building a homemade DIY bio-filter:

1. Prime the filter itself with some good quality bacteria. During the first few weeks it won't hurt to re-prime with more fresh bacteria every week or two. Just follow the directions on the packet/bottle. You should also do this at the start of your pond season now that spring in the UK is upon us.

2. I recommend adding a new dose of bacteria on a monthly basis throughout the year. This will boost any natural dying-off of the bacteria, and help renew any culture loss occurring as a result of any maintenance cleaning cycle, topping up the pond with tap water and so on.

3. You MUST be patient. You can expect the water to start to look cleaner due to solids filtration within a couple of days, gradually clearing over a couple of weeks, but the natural biological effect to clear the green water could take considerably longer, anything from 3 to 8 weeks depending on conditions. This would be exactly the same even if you had bought and installed an off-the-shelf unit.

The bacteria that convert ammonia to nitrate for us are among a class of bacteria that you may have heard of before. They are the so-called, “nitrogen fixing” bacteria. This means that they take nitrogen that is unavailable to plants in its ammoniacal form, and make it available to plants in an oxidized form.

These are the same bacteria that live among the roots of leguminous plants. Without these beneficial bacteria, life as we know it would cease. So be kind to your bacteria. What they need to survive is a large surface area, chemically inert medium and a ready supply of fresh water. They depend upon dissolved oxygen in the water to live and to do their job. As soon as the water flow is stopped, the oxygen in the filter becomes finite, and eventually gets used up. The ultimate result is that the bacteria die, and you have to start over. Also the bio-filter will benefit from a boost of new fresh bacteria on a regular basis, say monthly, to replace any that die-off naturally thus ensuring the process in the bio-filter continues un-interrupted.

To learn more go to my Biological Filtration and the Nitrification Cycle page

A good quality bacteria culture that I like and recommend (and is also used by koi-keeping professionals) is that from Bio-Claire
Their Bio-Claire® All in One Pond Conditioner can be obtained from most good aquatic supplies stores in the UK.