Blanketweed treatments

[estanque_koi]

A member of the A.E.K. (Spanish Koi Keeper's Society) has a problem with blanketweed. I believe he can improve his system to get better water quality, and that would help to control blanketweed.
However, he is asking for advice on treatments. I have never used products like BLANC-KIT KOI, AQUA BALANCE (NT LABS), BLANKET ANSWER (CLOVERLEAF), or the like. Do they really work? I would appreciate your views and suggestions.
Best wishes,

[mapleman]

Have you tried having a vegi filter which takes out the nitrates.The nitrates will feed the blanketweed.Have you tried Pond Balance ?.Interpet make it this kills the blanket weed fast it will turn the pond white/pink.Does not harm koi but need to check oxygen levels.

I have been using Eco-pure, made by Kusuri,it is a coarse powder which slowley works on the blanket weed and inhibits the growth.Need to use it weekly to keep it working.
Me gusta tu opiniones sobre carpas y tambien tenemos muchos carpas cual tuvimos por 20 anos. Lo siento, si los espanoles es malo.

[MikeM]

Evolution Aqua is marketing a product that is getting positive reviews. However, I do not think it makes much sense to use any sort of algicide except as a temporary fix. Unless the conditions contributing to the algae growth are altered, it is an expensive and risky step for temporary results ... risky because disintegrating algae harm filter efficiency and degrade water quality. Sometimes the algae will come under control if the water warms or cools beyond the optimal temperature range for the particular algae variety. Typically, adding shade and increasing water quality will result in better control. There are a lot of factors at work in the pond environment contributing to algae health, with nutrient levels almost always higher than needed to optimize algae growth. So focusing on shade is more likely to give improvement than any other single factor.

[dick benbow]

suggestion: check your water for phosphates. This is a huge contributor in many cases it's in the water and in the feed. A constant trickle of water can help to allieviate/slow the problem.

[bekko]

Blanket weed (string algae) will usually disappear in time. No one is sure of the mechanics, but it seems that there is a build up of some inhibitory humic compounds. Massive water changes and chemicals can bring short-term relief, but delay the natural inhibition.

If you manually remove it, you export nutrients (including nitrogen and phosphorus) from the pond as the stuff is thrown away. This helps starve the algae of nutrients and does not impact the build-up of inhibitory compounds. When I struggled with it, I made a metal fork on the end of a pole. The fork could be used to wind up the blanket weed - like winding spaghetti pasta on a table fork.

I do not know if the desirable short carpet of algae growing on the pond walls is the same species as string algae, but as string algae disappears on its own it gets shorter and shorter until you seem to end up with the desirable short form. It is all good forage for koi.

steve

[B.Scott]

Steve I fought the stuff your years without success. I tried massive water changes (up to 30% a day), draining the pond and sterilizing the walls with bleach, using Clarosan to poison it.
The only thing I have done that actually worked was to make a TT that put 50% of the water through it an hour. I used clarosan to kill off the week first and in combo with the TT it never returned. Clarosan alone will only knock it back for a month or so. The down side was my water went completely green for the whole summer. With luck it will reach a better equalibrium this spring and I will have no further trouble. That said i would rather have green water than stringy algae. The string stuff acts like a crap trap and keeps all kinds of rotten junk in the pond and NOT in the vortex where it can be flushed away. Bad news. My fish had all sorts of trouble and the water had a terrible level of bacteria. No more trouble now and health isn't an issue anymore.

[bekko]

Scott, glad you found something that worked for you. I guess if there was a "sure fix" the question would not be asked so often. Personally, I like string algae better than green water. At least you can get your hands on string algae to remove it and feel like you’re going something constructive.

You have seen the use of barley straw decomposition products to control green water. I am NOT suggesting that anyone use that. However, that is an intriguing and well-documented phenomenon. I am pretty sure there are some similar inhibitory compounds that somehow naturally control string algae. Maybe someday we'll know what they are.

steve

[B.Scott]

Steve,
How well it works remains to be seen but I am hopeful. The exact causes of string algae are hard to pinpoint. I have friend down the road with a tiny pond, same water sourse as I, far too many fish, nitrates at 100+ mg/l but he doesn't have string algae and his water is clear. Go figure.

I have always said the the person with the perfect solution to string algae will be able to retire in a year. But I'm afraid all to much of this stuff is simply snake oil.

As for the string vs green issue... All I can say is having stringy stuff like I had it is like hanging 4' long brushes along the side of the pond and completely covering the bottom with spawning rope. A greater crap-tarp has yet to be devised. I mean I had it a foot thick in the bottom and 3 foot strands from all the walls. That was with attempts to remove as much as possible every other day.
I've seen Bil get it but that amount is par to 1/10 of what I had and his pond is 8X the size.
Keeping fingers crossed X
B.Scott

[MikeM]

Bekko: There are several substances released into pond water by the algae growing in it which will inhibit growth of other algae species. It is a very complex subject involving alleopathy, competition for trace elements, preferential nitrogen sources, capability to compensate for low CO2 by breaking down carbonates ... it goes on and on. As a result of the complexity, it is virtually impossible to give anyone an accurate assessment of what they need to do to "naturally" control a nuisance algae.

Some years ago an experiment with pond water was conducted and reported in KoiUSA magazine. I believe it was Norm Meck who conducted the research. He took water from several sources, added nutrient and waited for the algae to grow. Invariably, pond water was the least productive water. Tap water produced far more algae growth. Do the experiment yourself. I think you will find that as long as you are careful to keep quantities identical and growing conditions identical ... say 16oz jars on the same window sill, distilled water with some fertilizer added will produce better than water from an established pond. (Of course, filter the pond water through a coffee filter or the like to eliminate algae already present. Leave the containers open to the air so algae spores can enter the water and perform during warm weather season when algal spores more likely to be present.)

His little experiment was consistent with many more technical analyses to be found in the literature. The precise identity of the substances released by particular algae is not well known. Many different poisons have been found in water samples. Undoubtedly some are released by one species and other poisons by other species. Each species is engaged in chemical warfare to make its environment conducive to its own kind. At the same time, each is removing minerals from the water, often storing nutrient beyond immediate needs, and as a consequence out-competing species less capable of efficiently withdrawing the particular nutrient from the water.

In my plant aquaria I see this every day. One tank is devoted to a Bolbitis fern, common Vallisneria and Hornwort. They thrive together. In another tank with identical water conditions is the ubiquitous Anacharis, Echinodorus and a different Vallisneria. As long as water changes are kept up to maintain a high calcium carbonate content, all is well. In the course of two weeks, however, the Anacharis is covered with flaky white scale ... residue from drawing carbon out of the carbonate in a low CO2 environment. At that point, algae will take hold on the leaves of the Vallisneria (a less efficient carbonate metabolizer compared to Anacharis) and it takes months to re-establish equilibrium. Once it takes hold, the algae is altering the environment to the detriment of other plant life. Meanwhile, Hornwort is known to retard algal growth in a closed system. Add Hornwort from the Bolbitis tank to the Anacharis tank? Won't work .... Anacharis and Hornwort repel one another. One or the other eventually fails. In my case, it is the Hornwort that fails, becoming algified in a period of days as the poisons released by the Anacharis do their job. But, the algae that smothers the Hornwort is not the same as the one using Vallisneria leaves as a substrate in the same tank! Why not?? ... I don't know. I can guess, but ....

So, my point is ... shade usually helps.

[MikeM]

PS ... if you want to learn about alleopathy, do a full web search. There is a ton of information available without visiting the local university library.