Normal Behaviour

[jevs]

You could theoretically get a little nitrate from rotting leaves, since they do contain some nitrogeneous compounds. In practice, I think the C:N ratio is such that any bioavailable N will get scoffed by the bacteria and fungi growing on them. It's still an input of N to the pond, just a relatively small one which will like as not get into the water column any time soon.

 

Yeah...i'm trying to think back on how that'll work....whether the "nitrates" produced by the leaves will show themselves as other nitrogen compounds such as nitrogen gas, i don't know. I'm pretty certain that Nitrate (NO3) would not be a direct product of leaves rotting. If it does....it would be an absolute minimal amount and be munched up by the bacteria as you mention, before it reaches the water column.

 

Nitrate also requires an oxygen-free environment to be eating (anaerobic) where nitrite must have an oxygen rich environment (aerobic) to get broken down. Many people will have encountered the anaerobic conditions in stagnant ponds......the smell of rotten eggs or hydrogen sulphide gas.

 

I'm off to consult my boys book of chemistry

[Ken Davison South Wales]

A couple of ideas to help:

 

a) Always buy a much larger pump than your filter requirements, it keeps us retailers happy and allows you to divert the flow inpart to filter and balance to pond via a water fall giving good surface movement which allows higher oxygen absorbtion.

 

If possible setup a marginal pond planted with reeds and other plants run the filter into this area to absorb nitrates.

 

30% via filter 70% down waterfall.

 

Try planting Gunnera manicata around the south side of pond gives shading when need in summer months, dies back in the autunm to allow plenty of light during short days. Again it keeps your local garden centre happy

[Bob on Stronsay]

There is another answer to this, fish are always on the lookout for a free meal. If you look in most well established pond filters you could well find blood worm and all sorts of free fish food, chances are they have got used to seeing this food and hang around for a snack.

 

Bob

[MrWiggly]

Hadn't thought of that Bob.

 

Funilly enough, every time I service my pond filter it is always full of little freshwater shrimps. Yet I have never seen any scooting around in the pond itself !!