Pea soup frustration!

Yes, that age-old problem. And it's driving me mad. The soup has arrived, spurred on by the lovely hot spell we had week before last.

My setup is an 800 gallon goldfish pond. 27 fish, most around the 5-8" mark (total length) and one 10" bigun. All very healthy.

Part of the problem is that the pond sits in full sun almost all day - can't do anything about that though. But the plants are growing well, most of the surface will be covered soon BUT this did not help last year.

Plants are two 2ft wide yellow flag irises, fully grown and flowering atm; one soft rush, also fully grown and just starting to flower now; and two water lilies. When these are at full spread they will cover over half the surface. Between those and the above, there'll be hardly any surface clear, but if last year repeats itself, the soup will still be there.

The fish are fed on basic floating sticks, 2-3 times a week. Filtration is very simple - I actually don't have a filter as such. What i have is a 40" plastic dog bed (no holes in base obviously :P), stood at the edge of the pond and full of irises (which are also well grown and just starting to flower, wee bit behind the ones in the pond). Water quality is brill - ammo/nitrite 0ppm, nitrate ~5-10ppm. This has been the best filter I've had by far, in nearly 30 years of ponds. The wildlife is good - frogspawn has been and gone, I've got pond skaters, diving beetles and so on. So all in all, it seems to be a well-functioning setup.

Yet still this blasted pea soup! I've used barely straw in the past which was good, but I'm at the point now where I want to work out why it's happening, when I think I'm doing everything right to prevent it; and to actually prevent it. I have blanketweed in there too but that's less of a problem - it's grown to about 6" and stopped. Not bothered about that. I used to have a UV when I had my last proper filter, but it malfunctioned and melted the housing and I've tried to go natural since.

This is the pond in full foliage last year, and you can see the dog bed filter on the right:



Any ideas?

 

When I did my pond, to help everything find its natural balance (which makes clear water), I bought some things I call 'pond bogies'. I can't remember the brand I used, but this is the type of thing I used.

http://evolutionaqua.com/acatalog/Pure_Pond.html

You simply throw a few in each week, and they dissolve to release lots of good bacteria, which then eats bad stuff etc, helping to achieve the natural balance. You have to throw a few in each week rather than all in one go because until the balance is achieved, the water is not right for the good bacteria so it doesn't thrive. With each dose of pond bogies, the ecosystem will modify slightly, until it become hospital for the good bacteria to thrive.

 

I'm by no means the expert on ponds, as you know, but from what I understand, having read about the product I used, the bacteria they introduce locks up the free floating nutrients, which feed algae, and then when the bacteria die (in their normal life cycle) they sink to the bottom, so in effect they mop free floating nutrients up and take them to the bottom where the actual pond plants have their roots. So, its just sort of moving nutrients down to the floor where your pond plants find them rather than the algae.

 

I tend to go for plants that live without any soil, adding soil adds nutrient.
Pea soup is a common problem this time of the year, and established ponds usually recover from that stage very suddenly, mine has done that in the last week.

Ponds take a while to warm up, and for the water plants to get moving, however the algae seems to just enjoy the sunlight, once the balance becomes right, the algae disappears.

 

Thanks all. The plants aren't exactly right on the bottom but their roots do reach the bottom - I don't have any shelves in the pond, it is as it looks in the picture: a box. Straight sides, 9' x 8' x 2' deep. Matt black liner. So all the plant containers are sat on the bottom. Holey plastic boxes for the lilies, and garden trugs for the rest with numerous holes in the sides. The roots grow straight out through these and down to make a carpet on the bottom. The irises in the filter have no soil - I just put them in there one year to see if they would grow on water nutrients alone and they are thriving!

I'd love to do a bog garden thing - it was the premise for the iris filter but it's the closest I can do at the moment. I do have a second pond liner, just a littlie at about 140 gallons but it's one of the irregular preformed ones so tricky to adapt for that purpose but that is my intention longer term. In the meantime I have another dog bed so I could always add an extra setup that way, I do want to get some different coloured ones with all the current stuff being from the same original plant but there's not enough room in the pond for them!

Could anyone recommend a better food perhaps (on Supa atm)? The fish get fed minimally to try and reduce the nutrient load but I am aware it's only cheap stuff so it'll have less nutritional fillers. I'd love to feed them all natural with frozen foods but cost does become a factor then!

 

The easiest and most sure way to get rid, is a U/VI'd go for one that is twice the rating of your capacity. The guideline is 10 watts per 1000 gallons, which I would double. So 20 watts per 1000 gallons.

 

Hi Freddy
I would certainly agree with the UV idea , My neighbour has a small pond only been installed about 3 months and had already filled with pea soup . Had filter and plants . Went out and bought a UV filter fitted it , 2 weeks later and a few filter cleans the pond is immaculate very clear .

 

Although I must agree UV lights do clear pond water, its kind of doing it via electronical means.

The water may still be full of nutrient but you dont know that, because the uv is killing the algae.
You probably never get the balance right.
Not really sure if that matters,
but it does to me, and my pond.

 

That's a fair point Pete. That's where regular water changes can help. Thing is, if the water is a pea-souper, it'll inhibit plant growth, imo. Also, it doesn't need a lot of nutrient for algae to flourish. As an aside (for those that might be interested), U/V doesn't actually kill algae. What it does is cause the algae to deform (Flocculate) whereby the algae forms into clumps and becomes large enough to be subsequently caught in the filter.

 

Water changes is something to be avoided, I always thought.

So a uv light would not work without a filter?

 

Nothing wrong with partial water changes. Obviously, if there's fish present, then a de-chlorinator should be added to protect the friendly bacteria in the filter. Without a filter, a U/V wouldn't be effective.

Yes, water changes do introduce chemicals, but a lot depends on your supplier. I can't say I agree about the nutrients. I used to regularly check the Nitrate level, and it was definitely helped by the introduction of 'fresh' water.
Of course, I'm speaking from the perspective as an ex Koi keeper. Water quality was key. In the Koi keeping world the motto is look after the water, and the Koi will look after themselves.

As to offering advice on 'natural' ponds, I have no experience, apart from total failure