Pond string algae in cold weather

[Mark Radell]

We have a small Koi pond and like many people we always get string algae in the spring. It's not a big problem and we are able to treat it with a single chemical treatment in most cases. However for some reason this year we got it over the winter, we had a very cold winter here in Louisville I'm not sure how or why it decided to start then. The chemical treatment we use is not effective until the water is at least 50°, preferably higher so that's not an option. Does anybody idea have any idea of how to get rid of it in a pond that is still cold?

 

[Patfish]

Mine in Ohio has a little and I have a grabber tool like to pick up trash. it is all plastic. I use that to get what I can when I see it

 

[Mark Radell]

We usually do too but this time it has almost taken over everything in the pond. We really can't pull out enough without screwing everything else up in the pond.

 

[Tula]

Do you have fish? If so, they'll probably begin eating it as the water warms, so pull what you can and let the fish munch away

 

[Mark Radell]

Yes, we have fish but a lot of the algae is in the waterfall area that they can't get to. In addition, from past experience, our fish don't seem to like eating string algae.

 

[Lisak1]

Welcome @Mark Radell ! Here's the thing about algae - it is not in and of itself a problem, but rather a symptom of a (potential) problem. In fact, the algae is both pointing to the problem and helping to control it at the same time. The problem is excess nutrients in your pond. The algae is consuming those nutrients and helping to keep your pond in balance. So before you kill it, you may want to consider what's causing the issue to begin with. Most likely causes are an overstocked pond or an overfed pond. Since you are coming out of winter, I'm going to guess that it's the former. Your fish are getting larger and are consequently producing more waste.

The other thing to consider is what happens when you kill the algae chemically. The result is dead organic material, which adds to the excess nutrients in your pond, which - you guessed it - grows more algae. Ideally you want the ecosystem in your pond to balance itself without the addition of chemicals. A better alternative in the meantime is to remove as much of the string algae by hand as you can - some use a stick or a toilet brush to wind it up like spaghetti on a fork! If you have a garden, toss it in. Your plants will thank you!

Tell us a bit about your pond - how big, how many gallons, how many fish, how old is the pond/fish, what kind of fish, what kind of filtration? The more info you can share the better we will be able to help!

 

[Mark Radell]

Our pond is about 250 gallons+/-and has been there about 18 years. The main pool is about 3' deep with a waterfall above it. The waterfall has multiple steps with an overall drop of about 2'. The waterfall effect with a 3200 GPH pump that draws water through a skimmer. There is mechanical filtration in the skimmer consisting of a net to collect large debris and a 2" thick course mat behind that to collect smaller debris. At the top of the waterfall there is a bio filter box with multiple layers of bio mat in it. We have no plants in the pond.

The pond has 5, maybe 6 small goldfish, the largest of which is about 4". The fish have not been fed since early last fall. There are no trees overhanging the pond area or even significantly close to it. We have the pond cleaned out to remove excess biomaterial on the bottom every couple of years.

 

[Lisak1]

We have no plants in the pond.

Bingo. You have no plants, so nature provides. Adding plants would be one way to balance things out.

Did you have your pond cleaned last fall? Do they break the pond down completely (i.e., drain all the water, take the fish out, hose things done, etc.) when they clean it?

 

[Mark Radell]

Yes, that's how we clean it. It was done last spring, we always do it in the spring to get rid of things that end up in it over the winter. We've never had plants because we don't want them to take over the pond which they can very easily doing one this small. We also don't have any plant ledges in the pond.

Having algae over the winter is not common, this is actually the 1st time we've had it. I'm especially surprised since we had a very cold winter here (Louisville Kentucky).

 

[Lisak1]

String algae actually prefers colder water.

Every time you break your pond down and clean it, you are basically starting over. "New pond syndrome" includes overgrowth of algae, string algae and pea soup (or suspended algae) being the two main culprits. The biofilm that develops on the rocks and surfaces in your pond are all part of the biological filtration of your pond. It's as important - or more important - than your manmade biological filter. Removing it by cleaning your pond disrupts the balance that nature is trying to create.

As for plants, what about adding floating plants like water lettuce or hyacinth? Both are easy to control and will definitely assist in removing those excess nutrients from the pond. You also said you have no trees near the pond and with no plants in the pond - does that mean full sun on the pond 24/7? That can also contribute to overgrowth of algae. Floating plants or a potted water lily would provide shade as well as pulling nutrients out of the water.

Just some thoughts!

 

[cas]

Welcome to the forum @Mark Radell !

In January of 2017, my pond lining was covered with string algae which stayed there all winter. This year so far, there is nothing on the sides of the pond. I can see the black liner. I have no idea why the difference.

I use to try to fight the algae but have found that having more plants, better aeration and once I start the pump in spring it goes away on it's own. I am actually embracing having the algae because it will handle the ammonia that my fish are producing until the other plants start growing. I'm actually concerned this year because I don't see any algae!

Here is a picture of the pond last spring. I did nothing to clean it. Once I started the pump, the lose algae made it's way to the skimmer (which I cleaned daily) and within a couple of weeks it was all gone.

 

[Mark Radell]

Thanks for the ideas Lisak, no the pond doesn't get full sun all day, actually it doesn't get a whole lot of fun at all. It's up near the east side of the house and there are some large trees about 50 feet away from it to the east and south so between the trees in the house it gets shaved for all except about 3 to 4 hours a day. I think we might have to try some plants of some kind though to see if that helps.

cas, we keep our pump running all year round since the pond is as much for decorative as it is for anything else. So that's not the issue. The largest amount of the string algea is in the falls and it doesn't and get to the skimmer. We mechanically break it loose but it's hard to get all of it loose.

I certainly appreciate the ideas and I'm sure we will get rid of it here as the season progresses.

 

[brokensword]

Our pond is about 250 gallons+/-and has been there about 18 years. The main pool is about 3' deep with a waterfall above it. The waterfall has multiple steps with an overall drop of about 2'. The waterfall effect with a 3200 GPH pump that draws water through a skimmer. There is mechanical filtration in the skimmer consisting of a net to collect large debris and a 2" thick course mat behind that to collect smaller debris. At the top of the waterfall there is a bio filter box with multiple layers of bio mat in it. We have no plants in the pond.

The pond has 5, maybe 6 small goldfish, the largest of which is about 4". The fish have not been fed since early last fall. There are no trees overhanging the pond area or even significantly close to it. We have the pond cleaned out to remove excess biomaterial on the bottom every couple of years.

Lisa is giving you great advice. Balance and you won't have long lasting problems. Plants will help you tremendously, even if you employ them in a bog/upflow wetlands filter system, which is OUTSIDE the pond.

Btw, I'm scratching my head trying to figure out the dimensions of your pond if it has 250 gallons and is 3' deep. Either it's very small surface area or the gallonage/depth is in error. I get 6" x 6" surface x 36" depth if you have 250 gallons. (LxWxAVG D x 7.43 = total gallons)

 

[zeuspaul]

A pond 6"x6" x 36" deep would have 5.6 gallons. A pond 36" x 36" x 36" would have 202 gallons. A circular pond 4 ft in diameter and 3 ft deep would have 282 gallons. This 4 ft diameter circular pond might be closest to 250 gallons because it may not be 3 ft deep everywhere.

The constant should be 7.48. When using this constant all units should be feet (not inches)

Btw, I'm scratching my head trying to figure out the dimensions of your pond if it has 250 gallons and is 3' deep. Either it's very small surface area or the gallonage/depth is in error. I get 6" x 6" surface x 36" depth if you have 250 gallons. (LxWxAVG D x 7.43 = total gallons)

 

[sissy]

If my fish don't eat it I use a toilet bowl brush and throw the stuff into my gardens