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

I have only had limited success with barley of any kind. I did have some luck with hydrogen peroxide, but I'm a little squeamish about using it and it is a bit controversial. Some people get very hostile about it, but I must say the algae disappeared pretty quickly after using it. I used one bottle per 500 gallons. The barley releases hydrogen peroxide as it decomposes, but it must be in smaller amounts. I ended up erecting one of those picnic tents over the pond to shade it from the sun. This has been the only thing that has really worked for me, other than the multitudes of tadpoles chowing down on it, LOL. I started looking at the advertisment flyers for the sporting goods stores, and found one cheap. This may not be an option for you, but here's a pic so you can see what it looked like. I used it during the hottest part of the summer. I have a koi pond "hybrid", rather than an actual watergarden. All my plants are in bog pockets at the pond's edge, but I usually put one Blue Beauty water lily in a sunny corner of the pond because they're so gorgeous.

no_regrets, Yeah, it's good stuff. I started using it and saw a nice clearing a couple of days later. It seems to be like a fiber for your pond system. Just helping it to be regular.... LP

Every time I clean out my UV pressurized filter, I collect the "waste" in a 5 gal bucket I use for the final rince for the filter pad. I then either dump the waste into the flower garden, or whatever tree looks thirsty. Everyone seems to be happy. I DO NOT add to my wifes tomato garden though. 1. She would kill me. 2. I add chemicals to the water everyso often, and don't think I want to eat them!