Hi everyone

I am new to the forum and have spent many hours browsing all the topics, and I must say that this is a fantastic forum. It's great to know that there are so many koi hobbyists out there that share information, advice, tips etc

With spring here, algae will soon become a problem in my pond. I have read somewhere that a Pleco can go a long way to solve string algae problems. I also know that Pleco's don't like cold temperatures.

My pond is 3000 litres, 1m deep, bio filter, 4500l pump, UV, 1m high waterfall...the pond is now a year old. I have 4 20cm Koi, and 7 10cm goldfish in it. Since new, one gold fish died for no reason, and 2 Koi have been eaten by a Heron. Other than that, no water related problems or fish diseases.

Has anybody had experience with a Pleco in the pond and do they really cleanup the algae?

Many thanks

Hi

Pleco fish will need a constant warm temperature and they will die soon in colder water. The mess they create will be more that the benefit of eating the algae.

Thanks for the reply.

I have also read that they get quite big quite quickly and that they may be aggressive as well to other fish.

I'm just so annoyed with the string algae, I have added another 2kg of salt a few weeks back and there has been no change, the algae is now 20-25cm long all over the pond sides and bottom. I have to manually scrape the algae off on a weekly basis. Chemicals don't work either.

The pond is in a shady part of the garden, just getting a few hours of morning sun. I have 3 lilly plants in the pond.

I thought a Pleco could be a natural way of getting rid of the string algae.

Thanks again

Viresco

http://www.koinetwork.co.za/Home.aspx?Page=UsrGeneric.ascx&Rec=228

Here is a link I found where a Pleco is resident in the pond. Nice reading and a very nice set up as well.

I think I am going to give a Pleco a go.

Remove the nutrients that the algae grows on.

Find the cause in your filtration that is leading to the high nutrient levels, eliminate that and the algae wont grow.

If you really are going to go that route, don't put the pleco in until the water is warmer and don't leave him in the pond over winter 15°C is the absolute minimum temperature for a hardy pleco.
I think the picture of the fish in Wayne Barker's pond is of a sailfin pleco (Pterygoplichthys gibbiceps) but the common pleco (Hypostomus plecostomus) may tolerate lower temperatures better.

I placed 6 of them in my pond a year ago and they all died two months ago, when my water temperature reached approximately 12 degrees.

Thanks, but while they were alive, did they keep the algae in check?

The temp thing is an issue as the last thing I want is for the Plecos to die when winter arrives again next year.

I do not think they made a big difference. Plants in your pond/filtration will control algae much better.

At risk of sounding like a stuck record or a nag.

Find the problem that is causingthe algae and fix it.

Root Cause number one. Too many Nutrients in the water coming from some where. This is what the algae grows on. No food, no algae, simple really

Sand filter? Open it up and stick your hand right down and turn it over, what does it smell and look like?

http://www.koiphen.com/forums/showthread.php?t=100547&highlight=algae

http://www.koiphen.com/forums/showthread.php?t=102060&highlight=algae

http://www.koiphen.com/forums/showthread.php?t=94835

A cut and paste.....

"The most important factor to address in algae control is the nutrients the algae need to grow. The nutrients that feed algae come from many sources and anything you can do to minimize the influx of these nutrients will help you control algal growth. Rainwater can be a problem since it carries air pollutants and particulates into the pond which can, in turn, increase the amount of nutrients in the pond water. Fish food, whether consumed by your fish or not, is another source of nutrients for algae. Food that is eaten by your fish is digested and excreted. The excretion is a byproduct of the fish food and a source of nutrients for plants and algae. Uneaten food rots and decays, this process provides ammonia and other nutrients found in the food to disperse in the pond water and allows algae to use it as food. Lawn and garden fertilizers are another source of nutrients. Water that runs into your pond from lawns and gardens can also be a problem. Lawn and garden fertilizers contain a high concentration of nutrients and can lead to major algae growth.

Nutrients can easily be controlled using some simple procedures. First, make sure that gutter downspouts are not directed toward your pond. This will help keep rain runoff from entering the pond. It will also help prevent fertilizers that may be present on the lawn from flowing into the pond. You will also want to build a slight, raised lip around the pond; this will divert rain runoff around the pond and help keep foreign particulates out. Good feeding habits also help in the control of algae. You want to make sure that all the food you feed the fish is consumed within about five minutes. Food not consumed within five minutes is adding harmful nutrients to the water. Finally, the introduction of additional plants to your pond can be very effective in algae control. Plants and algae compete for the same food. With enough plants, you can starve the algae of nutrients as the higher plant life forms consume the nutrients first. The use of oxygenating plants can reduce the amount of carbon dioxide in the water, which is needed by both plants and algae. The oxygenating plants, Elodea being the most popular, use the carbon dioxide in the water for fuel, and in turn, produce oxygen. Since the plants are using up the carbon dioxide, there is less of it available for the algae to feed. The increased oxygen content of the water increases the pond's ability to sustain life."

- www.peteducation.com

Also,

Q. I have a 2000-gallon koi pond that receives more than 10 hours of direct sunlight per day. Last year I experienced problems with hair algae and green water. What can I do to prevent these problems from recurring?

A. You've experienced algae problems because your pond readily offers algae the light and nutrients it requires to grow. Since you cannot feasibly move your pond to a shadier location, you must first limit the amount of nutrients in your pond, then incorporate natural algae control.

To limit the amount of nutrients in your pond, you need to stock less than 1 inch of fish per 10 gallons of water and feed only as much as your fish will consume in a few minutes. Also, test your water regularly for algae-fueling nitrates and phosphates. For residual control of phosphates, incorporate a chemical media such as PhosGuard into your filtration system. Lastly, consider installing a UV (ultraviolet) sterilizer in-line with your existing filter to help control green water.

After you've minimized nutrient levels, incorporate natural algae control into your pond. You can limit the amount of light that penetrates the water with floating plants such as water hyacinth and water lettuce. In other areas of the pond, add submersed plants such as Anacharis, Cabomba, or Hornwort. All of these plants – both floating and submersed - will compete for the same nutrients that feed algae, and will therefore help minimize algae growth. You might also consider adding lilies to help shade the pond and Japanese Trap Door Snails, which consume algae from rocks and pond decorations.

Thanks for this. It makes alot of sense. What I am lacking is plants to take more of the nutrients out of the water. I do have 3 lillies that are now about to start sending up new leaves, so I guess they will also come on stream and eat some of those nutrients, as we go through spring and they grow. I also need to add some hycinth to the settlement chamber and perhaps some shallow reed type plants. The salt I added a week ago also seems to be working as I don't see any more algae growth after I manually scraped alot out.

Well, off to the nursery I go.

Ed, where do you live?

i can help you out with some "water cabbage" LOL

i have too much, the stuff grows very nicely and i am going to have to throw some away soon.

Hi David,

Kan jy 'n foto van jou water gabbage plaas seblief.
Dankie

Jaco,

dis maar gewone hyacinth. dis hoekom ek " " gebruik het...

ek het in maart drie klein stukkies gekry en my veggie filter, return pump chamber en qarintine is nou vol van die goed. ek moet elke week weeggooi sodat die lelies in my veggie filter nie uit gestoot word.

Weggooi, behels, uitdroog en dan verbrand.

Fotos sal nog welkom wees. Dankie

ek sal so maak, more

Hi,
Some thoughts on this thread.

Where do the nutrients come from to feed the algae that grows in our ponds?

If the algae needs nutrients how come my swimming pool goes green without any koi if I do not add chemicals?

I had water hyacinth on my pond in the 1970's - these are the problems I experienced - firstly the koi ate the roots of the floating plants. So they died. Secondly I placed some on top of my filter chamber. This worked well and they grew quickly. One evening I was walking around the pond and noticed a rather bad smell. On investigating I found that the filter chamber - now completely covered was the source.

I pulled the hyacinth out and found that they have some parts of the plants for floating - a sort of round ball on the side of the plant. These parts of the plant were growing and dying rapidly and decomposing in the water under the plant. This was the source of the smell.

Remember this plant is classified as weed and is illegal. But it does work if used properly and you check continuously for dead material.

I have also seen a rather clever way of using this plant. A 40mm poly pipe - about 3 meters long. Place in the sun to soften. Then bend it into a ring and joint together. You now have a floating hoop. Take some shade cloth netting (low density so the water can move freely in and out of it) and place inside the hoop. This makes a floating basket for the hyacinth. And the koi cant get to the roots.

Salt added to the water will not control the algae - unless you add so much that you kill the koi as well.

You can control the stringy algae with salt - but used in a specific way. Firstly decide if the stringy algae is really a problem. If it on the waterfall or in the stream it is easy to control. If it is on the floor also easy. The walls are a little more difficult.

Shut the system down so that the water is still. Take the salt you would have added to the water, say 1 or 2 kg per 1000 liters of water. Do not dissolve this. Sprinkle the granules over the algae on the water fall as though you were fertilizing a lawn. You can do this quite heavily if you want. Same thing on the floor. Sprinkle the salt granules over the surface of the pond so they sink to the bottom and get into the algae. The walls can have salt dropped down the sides so that they get trapped in the algae as they fall down.

Leave the pond system off for two or three hours. The concentrated salt will kill the algae.

After this keep a watch on the pumps and filters and the dead algae comes away.

I have will post some more info on algae control under the thread on barley straw.

Any one know about using zinc oxide to control algae? And how safe this is?

Regards,
Chris

Hi,
A very good article to read on algae by Norm Meck. It may surprise a little with his theories. Norm has written some very interesting articles over the years.

http://www.koiquest.co.uk/GRENH2O2.pdf

Regards
Chris

I have used Viresco Aqua successfully twice now to kill a lot of blanketweed.

It is a bacteria and apparently does not harm the Koi even if you overdose.

I was about to try Viresco, but took Davids advice on filtration and adding plants and Chris tips with the salt, and I must say now after a few weeks, the algae has definitly subsided. There is still a bit on the sides of the pond, but the algae is no longer than a centimetre or two in places.

The mistake I made was to add more lillies and not to 'cover' the bases so the koi don't munch on the roots and the base of the lilly. I "inherited" a large koi and he has made a right mess of the plants.

So now I have a brownish bottom....clay all over the bottom! I am vacuuming so most of the clay is coming out.

Ed,

rather mix the clay into/with the Koi food.