Copper sulphate

[john5555leonard]

hi , does anyone use copper sulphate as an algaecide , Iv started using it in my swimming pool in powdered form and the water shines, I looked it up in my koi book and it gives the dosage as 0.2mg per 1000 ltr . Then today at the fish store there was a brand name imported Japanese koi food advertising it had copper sulphate in it for" bright shiny water" , but loath to use it without further advice, does it for instance build up in the pond and how often do you use it , any advice gratefully received , thanks , regards John ( Thailand)

[Manky Sanke]

John,

Copper isn't only poisonous to algae at low levels but it's also immediately poisonous to freshwater fish, such as koi, at slightly higher levels. The unscrupulous manufacturers of these algae based treatments rely on the user dosing the pond to a level that is poisonous to algae but not immediately poisonous to koi.

That's a tricky balancing act to maintain, especially with water changes and top ups that require the small additions of the treatment that will be required to maintain the level necessary to continue killing algae. This balancing act is achievable and so the suppliers can "prove" that their treatment has killed algae without immediately having killed any koi BUT.....

Even if the level is kept below that which will cause rapid death, copper accumulates in koi tissue especially with long term use. The correct term is that it is a bioaccumulative poison.

If you use these types of product on a long term basis, your koi will be less healthy and will probably die earlier than they would have done if you hadn't continually subjected them to a poison at a sub-lethal level.

There is a famous electronic device in this country, and maybe elsewhere, that I refuse to call anything other than the "Koi eXterminator" (yes everyone - that koi killing device!). A few years ago, the manufacturer tried to promote his Koi eXterminator on another forum by pretending to be a satisfied customer. To cut a long story short, his deceit was quickly exposed but he still tried to say that it was a safe and effective device. That was where I entered the thread and asked a series of questions that he didn't want to answer. He waffled his sales talk in an attempt to blind us with BS but I persisted in asking for the answers to my questions and he eventually abandoned the thread and ran away.

If you show my reply to your supplier and they try to disagree or to "prove" that I'm wrong then invite/defy them to come on here and debate the matter with someone who knows what detrimental effects copper has on fish. The last guy didn't do so well but I'm willing to give other koi killers the chance to prove me wrong.

[john5555leonard]

Thanks that's saved me a lot of grief , but I don't know what you mean about showing your reply to my supplier , I don't have one regards John

[Manky Sanke]

Sorry if I didn't make myself clear John,

What I meant was that if a manufacturer, supplier or seller of a product that contains copper as an algaecide tries to tell you I'm wrong and that the copper in their product is harmless to koi, invite them to debate the matter on here. I don't believe in confrontational posts but I have a series of questions that I would ask and then allow the readers of this thread to make up their own minds if the "supplier" has given convincing answers that prove I'm wrong and that the copper in their product will not harm koi.

Note: Copper in trace quantities only is an essential mineral in fish diets (and ours) because it is involved in the production and activity of many enzymes so it is frequently found in koi food and I have no problem with that. Trace quantities of copper in fish food refers to amounts typically in the region of 3 mg to 5 mg per kilo of food. These quantities are totally harmless to koi and also harmless to algae. Increasing the amount of copper to a point where it becomes harmful to algae means that the amount is way above the dietary needs of fish and, at that level, it bioaccumulates and becomes detrimental to fish health.

[john5555leonard]

Sorry my brain wasn't working this morning, you mean the shop , well it's a waste of time trying to explain anything to the Thais , even if he understood he wouldn't care , and he won't even be able to read the label on the pack if it's in English , lol my wife constantly tells not to bother trying to explain anything to them it will only give you a headache . Kind regards John

[Manky Sanke]

That attitude of the suppliers of a product being unwilling or unable to understand the downside of what they sell isn't just confined to Thailand, I'm afraid, John. I have near-permanent headaches as a result of trying to get simple answers to straight questions.