Sure. I'm glad to see some green in the pond. Some of my plants are still green.

I have some leaves in the bottom so that must be feeding the alga. I wonder if the Gold fish each some of it.

String Algae [Filamentous Algae] thrive in cooler oxygen rich water, especially when there are no other or few plants competing for the nutrients in the pond water.
Pouring Hydrogen Peroxide 3%, over the string algae will kill it without harming the fish and it can then be removed from the water.
"Horton"

I've got some in my pond and creek, too, Bugs. My pond plants look pretty pathetic since we've been having those sub-freezing temps (going on at least day 8 today), so I'm sure the algae is taking full advantage of the situation. :) I don't mind it, though.

Brenda

Brenda,
I am glad you brought up the fact that you don't mind the algae. I kind of like the look but isn't it going to be a problem in the end? What are your thoughts on just letting it grow? I am curious.

Here is a link that might be useful: My pond

Yep; that's the way my pond and water falls looked before the Deep Freeze hit. When the temps were in the 30s-40s, I had a lush growth of string algae in the streams and waterfalls -- not in the pond.

Now that it's sub-freezing, betwee 4-22 degrees every day, I have no idea what I have. Everything is covered with a thick coating of ice. I'm resigned to the string algae growing like crazy in the ice.

Oh well, in the spring, I'll put on my waders and remove as much of it as I can. One of the pluses and minuses of ponding.

I netted some out just the other day. It will subside when the plants come back, but scoop out what you can. I agree with the HP solution, but last time I said that I caught flak for suggesting it. Hmmpf.

If you kill it with HP you have to get it out because it only becomes more nutrients as dead plant material.

That bit on your waterfall is nothing to worry about IMO, but if you reach out with a clean toilet brush you can probably twirl if off somewhat. I had some bigger, loose gobs of it that I netted out, on the bottom. Nice addition to the compost heap and birds nibble it too.

CT

Bugs, I just let mine grow, unless it gets in the way of water flow in the creek or somesuch. My pond isn't at all formal, and I only have mosquito fish, so I pretty much let the plants, algae, wildlife, etc., have their way with it. I have plants growing in and across the creek, so I trim those back only when the birds start losing drinking and cleaning areas to thrash around in. Au naturale for me. :)

As I mentioned, though, the current cold streak has damaged (maybe killed? *gulp*) some plants I've had in the pond for a long time, like my huge umbrella palm. When it warms up, I may have to go pond-plant shopping for the first time in 3 or 4 years. :( The algae usually clears up when the plants start growing again.

Brenda

Hey!! Welcome to String Algae Season!! Gonna be this way until summer!

With HP (H2O2), what is the accepted dosage? I don't know of anyone who knows the answer. Too strong and it will do harm to all forms of life and not enough won't do anything. It will depend also on the clarity of the water since particles cause the H2O2 to break down into water and oxygen prematurely. If you start with concentrated H2O2 it can explode very easily (it is the oxidizer in rockets). If you start with dilute H2O2 it will quickly be extremely diluted in a large pond.

Much research has been done on the use of barley straw to prevent the growth of algae, but I am not aware of any such data on the effects positive and negative of H2O2.

So even though the recommendation of H2O2 may sound good and work for some people, it is a blind recommendation if no numbers and concentrations are given. Even if you kill the algae, the dead algae becomes food for new algae. Only a controlled continuous supply of H2O2 can control algae over a period of time. That is the reason many people believe barley straw works. And barley straw is know to only prevent the growth of algae, not kill it. That is a BIG difference.

One of the nice things about using hydrogen peroxide is that it is a rather "forgiving" chemical when applied to your pond. Dosages that have been used successfully by myself and others are in the one to two pints per 1000 gallons applied about 5 - 7 days apart as needed. Others have used dosages up to 10 pints per 1000 gallons claiming no ill effect on their plants or fish. The use of hydrogen peroxide is also used by folks in the aquarium industry to supply a slightly supersaturated oxygen level in the water or as a way to quickly and safely elevate the oxygen levels within a water that is not adequately aerated. Having said all of that I believe, as stated above, you have to use a bit of common sense when using it. Dumping a whole pint in one spot in a pond instead of spreading it around to help disperse it doesnt seem to be a very good idea. If you have loads of algae and you kill it what will happen as other bacteria breakdown all that dead organic matter? Obviously the oxygen levels would drop. This is not usually too much of a problem at this time of year since the dissolved oxygen levels at the current water temperatures (32° F in my area at the moment!) can easily exceed 10-12 mg/L as well as the rate at which your fish and the pond bacteria are consuming oxygen in cool water regions is significantly lowered. But again, common sense would seem to suggest to try to remove most of it physically before dumping hydrogen peroxide into the pond.

As to the "proven" benefits of barley straw: 1.) I am not aware of any peer-reviewed, scientific publications showing the specific benefits of barley straw demonstrated in a controlled, scientific study that says that it works. In fact, one non-peer reviewed discussion from someone with the appropriate credentials seems to suggest that the results from barely straw are a bit problematic (see the URL listed below). Furthermore you will find that many, if not most companies that were previously listing barley straw as an "algicide" on their websites and product brochures have been forced to remove such statements due to the lack of specific scientific studies to support the efficacy of barley straw. We can still use it and buy it for that purpose, theyÂre apparently just not allowed to advertise it for that. I use barley straw during the summer and consider it to fall in the "no harm" category... you probably canÂt harm you pond in using it and who knows, it might just help. I have yet to see barley straw provide any benefits anecdotal or otherwise once the water temperature drops below the mid-forties. The bacterial kinetics are just a bit too slow at that point. On the other hand, as Horton has mentioned above, string algae is very, very happy to be growing even at these cool temperatures. IÂve got a nice crop growing as we speak and canÂt run the pumps or filters during this time of year .... something about the temperatures going down to -15° F or so, freezing pipes, etc.! :-)) 2.) Of the reports listed implying the slow release of hydrogen peroxide in small amounts I have never seen any data where they have specifically measured peroxide levels either with or without barley straw. Many of the so-called studies discuss it, yack about it but I have yet to see a study telling me what the analytical method was that they were using to detect it or the levels they observed as the result of using barley straw. Yes hydrogen peroxide solutions can explode. Yes it is used for rocket fuel.....but not at 3% concentrations. Commercial/Industrial strengths can have up to 40% concentrations or higher with typical levels in the 10-12% range used in some swimming pool applications --- these are not the levels that the average pond owner is going to encounter. Long term storage of hydrogen peroxide solutions in chemistry labs is a problem due to potential hazards which I wonÂt bother to explain but this is not the issue for the average ponder or homeowner using 3% hydrogen peroxide and isnÂt trying to store it for more than a few months.

ÂDavid

Ah ha Prof, great to see you back in print after such a lengthy hiatus from the GW pond forum.
You have been sorely missed by many people.

I too was interested in where the average pond owner was going to find the high percentage strength of Hydrogen Peroxide, that would be used as rocket fuel and then use it to dose the string algae in their ponds?
Historically on this and other pond forums, the dosage has been suggested by many people to be effective at one pint of 3% HP per 100 gallons of water. Others state one pint per 1000 gallons, as David pointed out.
Some people have stated they have used the 3% HP at one pint per gallon, quite often over a season, to add oxygen to the water in their ponds after a thunder storm, when they have seen their fish gasping at the surface of the pond. They report no ill effects, to my knowledge, on the fish, plants or other pond inhabitants.

I have yet to read here or on any other pond forum or in any pond magazine or pond book, where anyone has had a problem using 3% Hydrogen Peroxide in either of the dosages afore mentioned to control string algae or add oxygen to the water when required!
"Horton"

Just wanted to bring this forward for kevip to read.

Correction.
"Some people have stated they have used the 3% HP at one pint per gallon,.............. to add oxygen...."
Should have read, ".......one pint per 100 gallons".
Sorry for typo.
"Horton"

WOW bugsb! That is sooooo.. cool! I'm jealous!

Got it I guess I am not as liberal with my Hydrogen Peroxide as I dont put in nearly that amount.. maybe I should increase a bit and do another scooping and cleaning.. this is my first winter so didnt know this would be a problem in cold water, I always thought the algae would die off in the cold water.. guess I was wrong

Are you sure that it is 1 pint per 100 gallons? I ask this because my pond which is approximately 15000 gallons would then require 19 gallons of peroxide and that seems like a lot.

That is the amount or dose that has been banded around for years on this forum, other pond forums and books.
No one has reported back with any misgivings or massive fish kills that I have ever read.

When I use it, I pour it slowly over the string algae, usually using no more than one or two pints when I see the need.
I do not treat the whole 2000+ gallons of water per se, I just use the 3% HP where the string algae is thickest and that does the trick.

We usually do not have a whole lot of string algae in the ponds, though historically it has been normally to have some in early spring, left over from the winter, and that I treat with 3% HP without any problems.
"Horton"

I use a bamboo stick to remove string algae I just stick it in the algae and turn, it wraps itself around the stick and pulls loose from the pond wall in one pond, and in the other the fish eat all the algae.