14 replies to this topic

[Bickley]

hey guys i recently put 2x ponds in my back yard. made 2x filters for them sort of gravity fed canisters. The smaller one has 6x 6cm koi and the larger one has 6x 15cm koi. I'm having a big problem with algae though mainly in the larger one which receives more sun. Its real stringy green algae like a web and is blocking up the fountain heads and making it less appealing. Im cleaning the larger pond every fortnight just to stay on top of it as best i can. Each pond has a 3500 L/PH filter with a T piece which approx half the flow goes to the fountain the rest up to the filters. The filters are 50% crushed clay 50% charcoal (recommended by pond store). Due to the positioning I'm limited in room to what i can do in a perfect world i would have a plant box filter.



What should i / can i do?
Is there anything i could put in there to clear the algae up ?

Edited by Bickley, 08 November 2012 - 06:00 PM.

[Anka]

There are algacides but they should be a last resort.

Go have a chat with Ollie at Aquotix and take a sample of te algae in. He should be able to help identify the algae and provide products or tips on a remedy

[Buccal]

Uv canister will clear up green water.
But algae growth on sides ?, well, you can't beat mother nature but you can work with it.
Ya gunna have to block direct sunlight of buddy.
Maximizing fish stocks will help in the way of grazing.
When fish are putting on growth and settled in, they will graze more constantly if you don't feed them to much pellet.
Algae growth is the system balancing out and will flourish as the nitrates build.
Once pond is fully settled and cycled, regular water changes to keep nitrate levels down will reduce the algae growth.
Nitrate is basically the algae fertilizer.

[bigjohnnofish]

maybe add a growbed and get some veges happening to reduce nitrate levels....

or get some lillys or other plants to cover a high percentage of the ponds surface area will help too....

and or throw some bristlenose in there as well!!! and maybe some snails also.......

but a UV is a good option....

your choice

[AXIS]

Personally I doubt bristlenose are gonna survive outside, especially in winter


More plants will certainly help though. The more the better.


And if you're having with green water barley hay in a hessian bag sunk really helps

[garlic shrimp]

like buccal said, uv and less feeding so the fish graze more algae,cheers.
Con.

[Bickley]

The ponds dont get direct sunlight there is shade cloth above them but the larger one on the right receives abit more light during the first few ours of the day as the sun rises above the patio.

I havnt been feeding them at all hoping they would graze on the algae and get it under control. Been around 3 months and only got a small feed

One thing I forgot to point out Is i have rocks in the bottom of the ponds, same rocks as in the garden bed don't know if that's a bad idea but the missus liked it so I went along with it lol

Don't really want to put to many plants in but sounds like that's the way to go. I'll probably go round the old boys and steal a bunch of lillies out of his ponds.

And buccal do you think i should bring the stock levels up to increase the grazing ??

Do Marron graze much on algae ?? Been thinking about getting some blue Marron for the ponds

[Rovik]

Adding small amounts of Hydrogen peroxide to your pond on a maintainance basis will get rid of your algae in time.
It decomposes slowly to form Water and oxygen....Hence the product is labelled "Oxy plus".

It does more or less the same thing as a huge amount of plants in your pond....Produce oxygen which "out competes" the algae, Only more efficiently and it cant die like plants can.
Algae doesn't like high Oxygen levels hence it "burns" and dies.

This is the same reason why we have numerous oxygen pumping stations on the canning river, To prevent algae blooms.

Perfectly Fine for the fish at respectable doses...They use this one in Aquaculture as well.
(Adding oxygen to the water during power outages or over stocked ponds)

BUT...(There is always a But)...

You mentioned the pond was only set up recently ? How long ago was that ?
If you have readings of ammonia and nitrite, don't bother.

Wait for your beneficial filter bacteria to colonise and consume the algae causing ammonia.

I strongly Recommend treating with peroxide if you have an established filter and your water quality is suitable.
The best possible thing to do would be to take a water sample to Aquotixs (>50mL), They will test it free of charge and recommend the best possible solution from there.

If your water has readings of wastes other an nitrate, Water change using a good quality water conditioner and reducing feeding.
Do you use a water conditioner when Water changing out of curiosity ?

Hope all goes well, keep us posted with your results.
Rovik.

[Bickley]

Ponds have been in for 8 months but the filters I made have been up and running for approx 6 months now.

[Buccal]

Yes more fish (adding only a few at a time) will help Im sure.
With more fish, each individual feels safer and at home, this will get them behaving more normal and grazing.
Don't forget we have just come out of the cold season.
The fishes metabolism speeds up from now on in with the water warming, and this means appetite will increase greatly.
Also at the time you set up your filters was the beginning of the cooling down seasonal period which would have lengthened the establishment and balancing of your pond.
Definetely take out rocks, they create unwanted dead spots or waiste collection points.
Keep up the oxygen levels and water changes, I find this tends to shock the algae.
Your advantage is they are small ponds and not a lot of water is needed for regular water changes.
It is much more sustainable for your own energy to work with mother nature rather than against it.
You can set up auto water changes weekly very easy.
A cheap timer from bunnings with a 1000 l/h pump plugged into it running the water as waiste out of the pond.
Tee of with poly retic fittings from your garden tap to your pond.
At the water entrance point to your pond a universal float valve from bunnings(plumbing section) used for toilets, water storage and many other things is fitted with constant water pressure running into it.
Set the timer for every Saturday running water out as waiste for one hour.
Ultimately some new water will be waisted with the old at expulsion point.
This method is set and forget and your pond will remain clear with healthy fish.

[Pat]

On the subject. My in laws-koi pond is about 3m x 1.5m x 0.5m with a black tile lining. It gets plenty of sun, has a UV light on the filter and a few potted plants in there. The water is always crystal clear but there is a healthy layer of algae that obscure the tiles. Not string algae. Just a green sheet. Is this unavoidable?

[Niz]

Just a quick note, Its not the suns fault.

Algae growth is the combination of light+excess nutrients+water flow.

I have had fish tanks lit with only sunlight for coral growth and with plants, and if you limit waste nutrients there is very little algae growth.

Feed less, water change more, reduce light with shade cloth, add more plants, increase filter surface area, increase water flow, will all work...but change one thing at a time and note the changes.

Give each single solution some time to work and balance, they don't happen over night. Find the one that works for your set-up and stick to it.

[Buccal]

Great advice, Niz.
Pat, I believe that thin non-invasive algae is part of the balance.
The algae is a plant and consumes to a degree unwanted nitrates and produces some oxygen and is a culture of food for fish grazing.

[Bickley]

Well I haven't really fed them since I got them so ruling food out. I since have removed the rocks/gravel in the bottom of the ponds wich I believe has stopped waste build up and the ponds are looking better no were near as much algae though time will tell. Going today to buy some more koi to increase the grazing and have thrown the fake lillies out and will be going to grab afew from my old boys pond. Hopefully this will solve the problem. And if the store has got them in will be getting some blue Marron to put in one of the ponds lol

Cheers for all the great advice guys good to know there's still people willing to give it lol

[Terry]

Lots of good advice above but don't forget algae cleans water. I have a 20000ltr pond which is mainly used to age water for the fish room, water filtered through algae is perfect for your fish. I use a rake once a month to remove blanket weed. A bit of green slime on the sides doesn't matter it lives on nitrates too. Green water can be a pain at times so a uv in the return pipe will get rid of it.