I've Inherited a Pond

Updated: 29 Oct 2006
What do you do if you inherit a pond? There might be living things in there that all your responsibility now!

A FORCED INTRODUCTION TO WATER GARDENING

It may be that you have bought a new house or you have taken on the cares of an elderly relative, and a water garden comes part and parcel with the new responsibilities, in which case this introduction to water gardening is for you. It is also a brief guide for all readers as to what state their pool should be in before they can begin to sort out their problems.………………

AAARGH! I’VE INHERITED A POND!

There you are, you have just moved into a house that is new to you. Fortunately, or not as the case may be, the previous owners or tenants built a pond in the garden.
" It were Albert's pride and joy that pond. " said the lady of the house when you first came to look it over.
"He used to sit out there and gawp into it for literally hours on end. "
Now it’s yours, and there are live things in it! And they might die and it'll be all your fault if they do!
So what will you do?
Check the remains of Albert aren't in there first!

FIRST OF ALL: DO YOU REALLY WANT IT?

Safety considerations

Safety is a prime consideration: Water to children is like a magnet.Safety is a prime consideration: Water to children is like a magnet.Seriously, there are things to consider in being a pond-manager. Although these are not necessarily of paramount importance and nor need to be attended to straight away, unless you have very small and very active children. If they are likely to try to get near it and fall in, fence it off. A low picket fence about 1metre high is best, or expanded diamond trellis, which can follow a gentle curve from one post to another.
Do not cover it over at this stage. This will only inhibit the normal to and fro of animal life in and out of the pond. You must clean it out carefully and sensibly first. You may decide to turn it into a child safe fountain feature for a while. In which case, after a clean out, you can
A. cover it over temporarily with a grill of weldmesh held be hooks rawl-plugged into the cement under the edging into the cement holding down the edging stones,Dougie Knight demonstrates his safe pond: large pebbles disguise slabs supported above the water on blocks.Dougie Knight demonstrates his safe pond: large pebbles disguise slabs supported above the water on blocks.
B. Cover the inside with paving stones with concrete block or brick supports from inside the pool. These can be covered with large pebbles and boulders. This leaves you t with the option of retaining any water falls or water features like fountains because you are leaving a reservoir of water formed underneath the slabs by the block work.

As the children get older you will see the value of a pond. It has a consistent entertainment value outstripping all the 'TV Soaps' put together for real life action and drama. A pool is also the most educational single feature of a garden, and it is for a good reason that the study of wildlife in the water garden is on the school curriculum. And you'll soon see why Albert spent most of his time "gawping" into it.

The Pond Environment

There should be a little self-sufficient world there, with every living thing dependent upon other living things or the sun and the nutrients that come from the perpetual cycle of life in a pond. If it seems impossible to see anything at all down there because the water is green, brown, milky or overgrown with a mat of roots and vegetative undergrowth, then you are looking at a job of work of do in the very near future.

A messy pond in need of a thorough clean outA messy pond in need of a thorough clean outAre there fish sitting very close to the surface gulping for air? Put a stick or a net and very gently feel for the bottom. Try to estimate the depth of sediment down there. If this causes bubbles and masses of organic debris to rise and a toxic niff pervades the air, then the job of work needs to be done as soon as possible. It needs to be cleaned out. There are products available that can help break down this organic matter but they need plenty of oxygen down there with them, they are expense and they only buy you time.
If the sediment seems pretty well decomposed and it doesn't smell then there is no panic. But remember what you are looking at is a balancing act between the different echelons of the world of plants and also of the world of plants and animals. Here we have a basic resource for the sustenance of plants and animals - water. Water just left by itself, will eventually become populated with the lowest form of plant life - algae. The myriad forms of algae can manifest themselves in huge quantities by turning the water green, or red, or creating green cotton wool effects, or blobs of slimy jelly.

In order to discourage algae, various representatives of plants from other orders need to be present:
Oxygenating plants ought to be there living below the surface provide oxygen for the animal life in the pond and also the essential bacteria that help to breakdown dead organicA new pond already green with single celled algae: The reaon is obvious. There are no plants.A new pond already green with single celled algae: The reaon is obvious. There are no plants. matter in bottom of the pond. As these bacteria produce nitrates as a product of the break down of this organic matter, Oxygenators and other plants use them up for rampant growth. Otherwise the algae would exploit the nitrates.
Lilies: don’t be too worried about there being too much oxygenating weed. Combined with the cover from lily leaves there should be 2/3rds pool cover from these plants combined. If either of them seems too rampant, only trim them back gradually over a period of several weeks. The pool environment has become dependent upon this oxygen supply and pool cover and you don’t want to disrupt it.
It does help to have a representative from the deep-water aquatic world, either a lily or a water hawthorn. These are gross feeders of pool nutrients, thriving in the maulm on the pool bottom and provide valuable shade that also inhibits algae.
Some lilies outgrow their welcome in small pool environments. So in late spring when growth starts again in earnest that is best time to haul them out and check the condition of the planting baskets. If they have outgrown them and they have deteriorated beyond recognition, they can be cut away and they new growth can be replanted if necessary.
Marginal plants: there should also be a goodly selection of marginal plants. Not only do they soften the edge of the pool area, but they provide cover for wildlife, an ornamental display and use up masses of minerals and nutrients in the pond.

The Problem with Fish

Koi carp need special careKoi carp need special careIn balance with this plant life, there should be no more than 18cm of fish per square metre of surface area (2ins of fish per sqft of surface area).

If you cannot tell one variety of fish from another, there are some that are very large and their front fins stick out sideways and they generally pretty colourful. If this is the case then you may need some advice from a local Koi keepers society. These beasties need special care and it needs someone with specialist knowledge to assess the situation. You may have inherited the responsibility of thousands of pounds worth of Koi carp!
Are there any fish with lesions or bits hanging off? White fluffy growths around the mouth or gills, white spots or the fish 'flashing' - trying to rub up against the side of the pool - are all signs of fungus, disease or parasites. This can be partially remedied with universal proprietary treatments. However, the only permanent cure is to improve the quality of the environment by improving the quality of the water and controlling the population. See other articles about improving water quality.

The Pond Liner
So now find out in what condition the materials are that have been used to create your water garden. Check the liner material particularly around the average water level. This is where it suffers the most, be it PVC, butyl, fibreglass or concrete. If the liner is perished, cracked or crazed, repair may be a waste of time, in which case live with it as it is until you have time to clean it out properly and replace the liner.
Ensure all the edging stones are secure and safe. If they all look as though they need some attention, check the footing that they are laid on and the relationship with the structure of the pool. It may be that the pool has no structure as such and the stone and or slabs are just laid onto a thin layer of mortar on mud. This would be a strong case for a redesign and start again.Checking the pump inlet for accumulations of debrisChecking the pump inlet for accumulations of debris

Pumps and Electrics

If there is a pump for a waterfall or fountain, trace it via the cable inlet over the edge of the pond or by the pipe work going out to the waterfall from the pond. Haul the pump out very carefully to see what state it is in. Check that the rubber on the cable is not perished. Make sure the inlet to the pump is clear. If there is a pre-filter to the pump - the foam or plastic box attached to the inlet of the pump - unclip it and wash it out in pond water or rainwater. If it's not going to be too difficult, try to see if the rotor blades are clear of debris. Next trace the power supply.

A trip switch like this sensitive RCCD must be installed between the pond electrics and the domestic mains.A trip switch like this sensitive RCCD must be installed between the pond electrics and the domestic mains.If there is a suitable protective RCCB (Residual Current Circuit Breaker) between the house electricity supply that goes out to the pond, try turning the pump on. There will be a switch on the RCCB and perhaps another between that and the pump, doubling as a connector to the supply.
If the RCCB 'trips', this may be damp in the connections or a faulty pump. Check the connections; leave them open to the air to dry them. OR renew them if necessary.
If the RCCB still trips then it is probably the pump 'shorting out', but if there are any lights on the same circuit suspect them first.
If the RCCB does not 'trip' but the waterfall or fountain still does not work, switch everything off and remove the pump from the water. Detach it from any pipe-work or remove the fountain jet and put it in a bucket of clean water and then turn it on. If it bursts into life, clean out the pipe work or the fountain jet. There is probably a blockage of algae somewhere in the pipeline or jet. Stiff wire, water pressure from a hose or a combination of both usually works eventually.
If however the pipe-work seems quite clear, there may be a rise in the pipe that causes an airlock to get trapped in the hose. This can be quite an effective buffer against the push of even quite powerful pumps. Try to ensure a smooth run of pipe-work avoiding a roller coaster effect. If that seems to be the problem and it is something you can do very little about, try switching the pump off and on a few times. This eventually jerks the airlock away in one direction or another. The other method is to detach the hose from the pump and run a powerful hose up it until it is flowing consistently out of the top end then quickly fit it to the pump and turn it on immediately, if it is not already running. This is the sort of exercise that ends up with someone getting soaked.

Troubleshooting the Pump and Servicing

Direct drive sump pump usually has a removable baseplate that allows access to the impellorDirect drive sump pump usually has a removable baseplate that allows access to the impellorIf the pump seems to just hum expectantly or rattles and whirrs, check the rotor blades for small stones and debris to see if they can rotate freely.

To remove the rotor usually requires a certain amount of dismantling:-
Direct drive pumps (these sit upright with the in take on the bottom and the outlet on the side) generally have a sole plate held on by four screws. Another plate that sits just over the blades, can be just prised off.

Induction motors (usually sit long ways on the bottom of the pond ) just untwist apart or unclip.The old Blagdon Amphibious pump can be taken to pieces completely: The only bolt holding the rotor in place has a lefthand thread.The old Blagdon Amphibious pump can be taken to pieces completely: The only bolt holding the rotor in place has a lefthand thread.

In Blagdon Amphibious pumps the rotor is held in place with a left-hand threaded screw. Check for any wearing surfaces and the quality of any washers or bearings. There should be very little excess play either sideways or backwards and forwards.

After cleaning the blades, put it back together and try it again in the clean water. If it is still noisy but with very little action then it is highly likely a bearing has worn out or the rotor blades have sheared off the spindle. This spells 'death' for the direct drive pumps, but the manufacturers of the better induction drive pumps supply new bearings, washers and seals kits for their pumps. You may have to remove the pump to take it to your nearest dealer to get his opinion. (N.B. Try to get some sort of reassurance that he might know what he is talking about.)

Removing the Pump

Coiling the threads of wire round the draw cable before taping them back.Coiling the threads of wire round the draw cable before taping them back.Before you pull the pump cable out of its conduit or pipe to the side of the pool, when you disconnect the pump from the electrical connection, attach a piece of wire or strong string (a 'draw cable') 10metres long to the pump cable at the connection end.
Do this by making a secure loop in the 'draw cable'. Feed the exposed wire on the pump cable through the loop.
Twist and fold them back on themselves and bind them in place with insulation tape. Check that the string and cable are well attached by trying to pull them apart. Then gently pull the pump cable, from the pond end, down through its conduit. This will pull the draw- string through as well. Then you can undo it and leave it in place when you take the old pump away to get it serviced or to get a new one.
It may be the case that the pump did not trip the RCCB, nor did it express any hum of disapproval at any attempt to revive it. In which case remove it from the pond environment and try it on a workbench plugged into a different mains circuit. Switch it on very briefly and don’t touch it whilst the power is on. Any activity proves that there WAS something wrong with that outside circuit. So if the prospect of checking it properly with a meter or circuit tester seems daunting, call in the electrician.

FILTER

There may be a biological filter installed. This should be outside the pool with water running into it from the pond (usually pumped there by a submersible pump) generally discharging backBiological filter box complete with ultra violet lampBiological filter box complete with ultra violet lamp into the pond or the header pool of the stream at the opposite end of the pool from the pump. It must be still in operation even whilst you are moving in. If it has been switched off for more than a couple of hours, you may as well clean it out so that you are safely able to start again. This must be emptied out and the various bits of media and plastic foam washed and rinsed through with (preferably) pond or rainwater. Clean out the pump too (see above). Put it all back together making sure the outlet is perfectly clear when it is running and that the water is not spraying or dripping out from underneath the lid. Allow at least 1 month for it to start work biologically i.e. digesting the muck and algae that get pumped into it. Up until then check that it does not get too clogged up, as it will still be working mechanically.

U/V (?)

There may be an Ultra violet lamp in tandem with the filter on the inlet pipe. This 'zaps' algae dead as they pass by on their way to the filter. The lamp in this needs changing every 6 months to be effective. Very, very carefully pull off the end caps to reveal the lamp tube and slide it out. If it is getting a bit old and inefficient, the gas inside will be darkening the ends. Ease off and replace. Do not touch the glass and do not look at it whilst it is switched on.

The u/v lamp bulb or tube should itself be sitting within a quartz tube. This should be cleaned regularly too, but if you are in any way ham fisted (like yours truly) approach this task with a certain degree of trepidation! They are not cheap to replace.

“FOOLS RUSH IN WHERE ANGELS FEAR TO TREAD”: Alexander Pope – Essay on Criticism (1711)

If there is no desperate emergency, but a pool cleanout is on the cards, leave the cleanout until October or before the frogs do their business at the beginning of March. In the meantime read this online magazine regularly as there will be constantly replenished articles on how to deal with pond problems and many will be relevant to you.