On 10 Feb 2017 14:41, JBL2527 wrote:

Always had a garden pond with goldfish/grass carp, water circulation and
plants etc.
Last autumn we moved to another house. There is a well established, well
built pond, circular, approx 3m diameter and over 1.5m deep. There are
just plants in it. No shelving sides just straight down !.
There must be quite a lot of fermenting vegetation at the bottom as it
bubbles away in warmer weather. No fish.
I like fish. Not an expert, I just like to see them, just ordinary
goldfish.
I rather think that I must improve the water quality and oxygen content
for fish to survive so…..
1. Oxygenating plants. I can get a variety but do I let them float on
the top or sink them to the bottom ?
2. Water circulation. Outdoor power is available so I can put in a pump.
This could power a waterfall feature ( had one before and plenty of
stone available to build one) plus a fountain of some sort.
Would these measures enable fish to survive or do I need to do more ?
If this is OK then how long before I can put some fish in ?
Any ideas or suggestions gratefully received.
Thanks all.
Brian.


The first thing you need to do is clean the pond of dead vegitation and
detritus. Best done in spring now as there may be sleepy amphibians in
there. Filthy job even with a swimming pool hoover. The detritus is
a very strong manure so use it but carefully, seen it burn grass.

Once that job is done and the water settles down you will probably be
able to get a few goldfish. However, they normally breed or you want
more than a couple so a pump and biological filter system would enable
you to keep the water in perfect condition, the nitrates, nitrites, low
and the fish healthy. It will also help increase oxygen in the water
and allow gas exchange. Let it work for a week or so before introducing
some fish, and do that slowly too over weeks, it takes time and need
food (from fish waste) to grow the bacteria and to start working. Put a
filter on it without cleaning it out and the filter will clog up
quickly. You might consider adding a UV filter to keep the water from
going green in summer and kill off some of the parasites etc that
attack the fish. Biological filters have to work 24/365.

A fountain would preclude you introducing a water lily as they cannot
cope with constantly wet leaves. I would personally introduce a water
lily or two to give summer shade for the pond. Helps keep it clear too.

Named quality varieties can be obtained from specialist nurseries
like...
http://www.lilieswatergardens.co.uk/
Make sure they can take the depth of water above the pot that
you will have. Gladstoniana and Newton spring to mind, they will need
annual feeding too with Osmocote tablets (they are gross feeders).

Oxygenating plants are good except for one thing, at night they reverse
the process and breath out carbon dioxide, that is nearly always the
cause of mystery pond fish deaths after a hot sultry night. Never had
any such plants in my pond which we had for 30+ years. With a
pump/filter they are not needed.

I might add that fish do like somewhere to hide especially at first so
a clean clay flower pot on it's side at the bottom will make them feel
more secure. You can tie a string around it so it's easy to get out
although I would leave it there.
--
Regards
Bob Hobden