When to clean the pond?

[lumpyjumper]

We inherited a medium sized pond when we bought the house about 5 years ago. No fish but we put our daughter's two goldfish into it and now we have over 50 fish! All have survived and indeed thrived even though we never feed them, but we'd not used a filter and so the water was getting a bit murky.

We netted the pond in autumn to stop the majority of the leaves from falling into it, and this summer we treated ourselves and the fish to a filtration system. The water is much much clearer already although we have to clean the pump daily at the moment.

The question is, the bottom of the pond is still a mass of decaying vegetation and I imagine 5/6 years of fish poo. If we scoop it up the water is full of suspended silt for several hours. How and when would be the best time to get in there and scoop it all up in one go? The fish are displaying signs of definite mating behaviour at the moment and I don't want to disturb their eggs if they are down there, nor cause them too much distress.

Thanks so much, we're real novices at this pond thing.

[Kristen]

I don't know anything about ponds, but is there a chance that the fish are using the bottom "mud" to snuggle into during the cold winter months?

[lynda66]

the mud at the bottom is full of decaying matter which isn't good for them, but now you should leave the pond cleaning till late autumn, when all the breeding behaviour has stopped, otherwise you remove the insect larvae they feed on too, this is important if you aren't feeding them, but while the fish are still active. or, you could get a pond vac to remove the silt ..... you can get some liquid that binds algae together so you can scoop it out with a net or vac it up. (cant think of what its called now, but they will know what you mean at the pet shop)

whilst they are breeding, they use lots of energy, so you should really be feeding them to supplement their diet, and also feed them when you have cleaned the pond, as you will remove much of their food source.

i have a filter too, but clean the whole thing out usually in spring as the weather starts to get warmer, and when the fish start to surface after their hibernation. empty the water by turning the filter round into the soil, or into buckets and use to water flowers or veg, and put the solids on the compost heap.

Lynda xx

[lumpyjumper]

Lynda thanks so much, just the advice I needed, OH is desperate to clean the bottom as he is having to clean the sponges of the pumps daily to keep the water flowing through the filter.

We have just (yesterday) bought a pump cage with a foam filter so that it might last a bit longer between cleans. We have also lifted it about 6 inches off the bottom but it still clogs daily.

I was sure it was the wrong time to be dredging the bottom of the pond but it's sometimes hard to persuade him

[lynda66]

i use old towels on top of the sponges when the water is really grotty, filters out more gunk, and you can just take it off and rinse, the sponges dont get so dirty then, when the towels are really grotty and you can't get the gunk off them, stick them in with the compost.

don't put them in the washing machine though, as you'll be trying to get rid of the smell of fish s**t for ages

[Herbgardener]

and don't clean them out in tap water, use a bucket full from the pond.. the sponges should develop colonies of good bacteria, but if you blast them under the tap they won't.

[lynda66]

oh yeah, and when you clean the pond out, keep half of the pond water if possible to put back in ....... or you can get water treatments so it's safe to put them back in tap water when you've refilled it.

[Stacey Steve]

To keep you going till autumn, try standing the pump on some house bricks to lift it out of the sludge at the bottom of the pond, then you will be filtering the water but not lifting the mud.

Make sure though that you scrub the bricks first with a bucket of water out of the pond.

[lumpyjumper]

So in the Autumn I'll empty the fishpond, save half the water and the fish! will a paddling pool be ok, it won't be for long I suppose?

Clean out the sludge from the bottom of the pond and sling it on the compost heap.

Replace the fish and the water and top up with tap water or would my water butt water be better?

About October time?

RE:bricks, the pump is already on bricks and two pieces of wood to try and lift it out of the sludge, I have to assume the sludge is REALLY thick as I've just got home to find the fountain is but a trickle and the filter is a mere dribble again, OH will be most disappointed when he arrives home in about half an hour. Shall suggest the towels idea. Also he's been cleaning the sponges in the pump with the hose rather than with the pond water will that make a big difference?

[lynda66]

yes, i always put mine in the paddling pool to clean it, not sure about the water butt water, i guess it depends if it's fresh or green or smells, i'd probably go with the tap water to be sure?

yeah, september october should be fine, just make sure you feed them until it goes cold and they stop coming up, as you will have removed all their food.

to be honest, with how your pond sounds at the moment, i don't think there will be much problem with doing it with the hose, but once its all clean and sorted, you should always use pond water. the towels just need replacing once or twice a day whenever the flow slows down the same, but it should help with the sponges getting full.

if there is that much sludge, can you use a net to get rid of a lot of it? scrape it along the bottom, and you should get lumps of it coming out ..... a kids fishing net should be ok but if not fine enough, use the net with a leg of an old pair of tights over it.

[burnie]

50 fish in a pond sounds like about 40 too many.There is a formula for size of pond in gallons to inches of fish you can sustain properly.To be honest,read up and decide what you want,if it's a clean bottomed fish pond,then lots of filtration and no wild life or plants and feed your fish.Alternative is a wild life pond and no fish,any thing in between is likely to give you unhappy fish.

[lynda66]

depends how big the pond is, and plants help stop heron predation, and help keep the water clear, and provide oxygen.

[lumpyjumper]

We have been using a net to dredge the bottom, heavy great clumps of leaves are brought to the surface and then the silt is in suspension for a few hours, I was concerned about the effect this would have on the fish.

The fish seem to have limited themselves in terms of quantity, as I said we started with 2 large ones and the 50 odd we now have are all of a smaller uniform size, just variations of colour as there was obviously a black fish left from the previous owners They seem perfectly happy and play in the fountain, hide under the lilypads etc.

Since we started the filtration, the oxygenating weed has also grown which previously it hadn't so i think we're starting to get the balance right. It's just the decaying vegetation at the bottom that still causes us concern.