Normal Behaviour

[Elton]

My fish always hang around where the water re-enters the pond from the filter system. Obviously, the oxygen is better there.

 

Is it normal for them to do so, or does it indicate a problem elsewhere?

 

I have a lot of rotting leaves in the pond and wondered whether this affects oxygen levels.

[jevs]

As water temperatures increase, so the dissolved oxygen levels in the pond decrease....especially at night when any pond plants you have will be taking in oxygen and emitting carbon dioxide.

 

I have a large air pump on my koi pond with 8 large air stones. This is a bit over kill for a small garden pond but if you can find a way of getting some air into the pond like that, it'll make the fish a lot happier and healthier.

 

Although the rotting leaves are not particularly desirable, i wouldn't think they would play any significant part towards oxygen depletion.

 

Hope this helps

 

Andy

[Elton]

Cheers, Andy.

[argyll]

Mine are hanging around the outlet too, its the most comfortable place in this heatwave. Finally got my dodgy airpump working over the weekend. Any extra air that you can give will be appreciated and the cleaner the pond the better.

[Alan Hammond]

The rotting leaves will be adding nitrate to the water which you definitely do not want. If you can I would get rid of them. There are several products on the market that will help to break them down safely. I would also consider a fountain of some sort to disturb the waters surface and thereby add aeration. You do not need anything fancy, in my own pond I just let the water spurt up from an open pipe connected to the fountain outlet on the pump. It actualy looks more like a natural spring than a fountain and does not clog up every time I turn my back.

[Elton]

I'll try to get a photo of mine later.

 

Basically, I've got a powerful pump that feeds through a filter and then down a waterfall. I raised the end of this a week or so ago, so that the water now falls into the pond.

 

With regards to the leaves, I think I may get a proper pond hoover. I did have one that connected to the hosepipe, but never got on with it.

[jevs]

The rotting leaves will be adding nitrate to the water which you definitely do not want.

 

Sorry mate but i would have to disagree with you there. Rotting leaves will produce humic acid which will turn the pH of the water slightly acidic (coldwater fish prefer a pH of around 7.5).

 

Nitrate is produced as part of the nitrogen cycle which goes like this

 

Fish are fed>>>>>>>fish excrete>>>>>>>>fish waste produces ammonia (lethal to most fish)>>>>>>>bacteria in the filters break ammonia down into a slightly less harmful nitrites>>>>>>>>another bacteria then breaks down nitrites into nitrates which are virtually harmless>>>>>>>nitrates are removed by water changes and also help feed any plants you have plus algea (green water and blanket weed)

 

Personally, the rotting leaves are undesirable but not critical. You are better off getting a good air pump and chucking in a few air stones.....or creating more surface agitation by a fountain as mentioned.

 

Hope this helps

 

Andy

[Alan Hammond]

Stand corrected. It has been a long day, I was fishing at four o clock this morning. Mind seeing as to how I was at the W.A.C.A.C. water at Brenkley I would have been better off staying in bed. The more so as I had to follow a five mile diversion to get there.

[MrWiggly]

My fish were doing the same ...

 

I have dragged a small pump out of hibernation, connected a length of hosepipe to it, and chucked it into one end of my pond.

 

The other end of the hosepipe I have "narrowed down" with a small nozzel to increase the exit pressure. This end if the hosepipe I have sited just above the water surface further down the pond.

 

I now have a strong jet of oxegenated water blasting across my pond.

 

The fish are loving it !!!

Edited July 7, 2006 by MrWiggly

[Steve Walker]

Sorry mate but i would have to disagree with you there. Rotting leaves will produce humic acid which will turn the pH of the water slightly acidic (coldwater fish prefer a pH of around 7.5).

 

Nitrate is produced as part of the nitrogen cycle which goes like this

 

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.