String Algea has ruined our pond Help Please

[lasadelfas]

Hi everyone I am new to this forum and will be most grateful to any messages I receive in relation to this major problem with our fabulous pond. I live in southern Spain in the countryside away from the busy Costa del Sol. It is a wonderful place to live but as with anywhere there are problems and my problem is string algea.
I am at my wits end with this dreaded string algea. This year has been the worst year yet. All our fish have died and the water lilies are not growing as usual for this time of year. Frogs and water snakes are doing well!!! I will give you a brief history of the pond.
We didn't construct the pond it was a feature of the garden when we purchased the house in the year 2000. The pond has been built with stones and rocks, not with liners or any modern fabrics. It is fed daily with fresh water via the canal system we can also turn on the waterfall feature which keeps the water aerated.
The pond was fantastic lots of fish and lilies, the water was clear and the pond was very healthy. This status quo lasted for quite a number of years, then in about 2009 we first encountered the string algea , it arrived quite suddenly growing around the edges of the pond. Also when I first noticed the algea in the pond , I saw in the shallow water at the river side, this algea was growing, as our water for the pond is from a canal system which starts at the river, I thought that this is how the algea arrived in our pond. I checked on the Internet as to how I could get rid of the algea and found that you need to remove it, by scooping it out. The following months I scooped out the offending algae. This seemed to work and our pond remained in good order over the following years, when ever I noticed the algea I removed it and all was ok. Fish were breeding and so were the lilies.
Until last year, Autumn time. The algea started to bloom. During this time our fish disappeared, some to the heron but others just disappeared. We then took action and removed all the papyrus plants and roots, we then sucked out all the sludge from the bottom of the pool and refilled the water. Within a day the algea was growing. We removed again all the sludge from the bottom of the pool, still the algea remains. Daily we fished out the offending algea, but it seems to have taken root, the sides of the pond and any roots are covered in the dammed stuff. From what I've read it seems that we need to remove it totally before we can place in the barley straw, that is the problem, when it's stuck like glue to the sides of the pond and the roots of the water lilies. How can we remove it? Now our pond looks like a witche's brew and daily I scoop out the floating algea but by the following day the pond is covered again. It's a nightmare! Please any suggestions will be most welcome and appreciated. The weather is heating up at the moment and I feel we cannot leave the pond to the attack of the STRING ALGEA.

 

[j.w]

@lasadelfas
Never really had the string algae issues but have heard some use a clean toilet brush to yank it all out. The flat algae that sticks to the sides of your pond is good stuff but I think you are talking about it being long and stringy on the sides also. Others have mentioned hydrogen peroxide as that is what the barley straw turns into as it decomposes. Perhaps someone will post something more about what they know about it. Hope you can get rid of it. Google hydrogen peroxide for use in removing string algae from ponds.

 

[addy1]

Welcome to our forum.

It almost seems as if the canal water has gotten more nutrients in it that is feeding the string algae.

In a pond in the past, I used hydrogen peroxide to remove the string. I would add 1 liter to 1000 gallons of water. Be ready to remove the dead algae.

 

[bagsmom]

Yes, one thing I learned from this group is that dead algae can add nutrients to the water and make MORE algae. So it will be important to get rid of what you can. Do you have any plants left in the pond? They should help suck up nutrients. How much sun does the pond get? Could the sunshine be contributing to the overgrowth? Does the waterfall feature have any sort of biological filtration in it? If not, I wonder if you could add some? I know this has got to be so frustrating!!!!!

 

[mgmine]

Tell me about it! I get it from the spring water that I use. It is so thick that it almost shuts the stream down. Here is a video of how I get rid of it. I have since learned that you don't have to scrub it just put it on and let it sit for a few hours. Once the pump is turned back on it slowly washes everything away, usually within a day.

 

[JamieB]

I’m inclined as well to think you have something contributing upstream, fertilizer run off, something along those lines. As your pond gets a steady flow daily of that nutrient rich water, all you can do is find ways to reduce it in your pond. String algae is an unsightly symptom that something is wrong in the water. Test the water going into your pond, check nitrate and nitrite and ammonia levels. If those are above zero, I see two options. Either block off that water from your pond and add only dechlorinated tap water, or you could do a bit of renovating, and create a bog filtration to use up the excess nutrients and starve the algae.
The other issue you mentioned was your water lillies are not growing like normal. Issues could be a shortage of iron, algae is taking up nutrients they normally get, or they may need to be divided as they are getting root bound.