[fry lover]

Hi All

Just joined, basically i am into fish-keeping and i am particularly interested in the science of fish keeping, especially water chemistry.

Can you help me with this please, and if it needs to be in a different forum please advise so i am best place to get good feedback, thanks.

What follow's below is a cut & paste from a thread i did on a fish forum, where i am not getting any answers to my question.



Waterlife Protozin (fish med) contains Copper Sulphate at 0.015% w/v, i believe this equates to 15mg per 100mls, from the instructions on Protozin, if you had a 100 litre tank, you would end up dosing a total of 1.005mg of Copper Sulphate (or 0.01 mg/l)

Interpet Anti Slime and Velvet containts Copper EDTA at 3,750 mg per 100mls which i believe is 3.75% w/v. from the instructions on the product, if you had a 100 litre tank, you would end up dosing a total of 1428mg of Copper E.D.T.A (or 14.28 mg/l)

Now from looking around on Google i found this explaination around E.D.T.A

E.D.T.A. (ethylene diamine tetra acidic acid)
USE: Chelates and inactivates heavy metal ions such as calcium, iron, copper, and other tri-plex ions. lowers pH.

I also found this

EDTA (ethylenediaminetetraacetic acid) is a common sequestrant and antioxidant added to foods, body care, and household products. It occurs as disodium calcium EDTA, tetrasodium EDTA, and disodium dihydrogen EDTA. As a sequestrant, it binds trace minerals such as copper, iron and nickel that may be in the product. If not inactivated, these minerals will lead to discoloration, rancidity and textural breakdown. When added as an antioxidant, EDTA prevents oxygen from causing color changes and rancidity.

What i want to know is, what's the difference in Interpet using EDTA at 14.28mg/l per dose and Waterlife using Sulphate at 0.01mg/l per dose?

What product has more actual copper in it per dose?


Many, many thanks if you can help with this..

another thing i am curious to know is, how long does copper stay "active" in water do you think (for the purposes of fish tank medication), or does this depend on too many different variable's, including what type of copper is used?

[Borek]

What i want to know is, what's the difference in Interpet using EDTA at 14.28mg/l per dose and Waterlife using Sulphate at 0.01mg/l per dose?

What product has more actual copper in it per dose?

Trick is copper is complexed by EDTA, so even if the total concentration of copper seems to be higher, concentration of free Cu²⁺ cations (which are poisonous and as such effective against whatever you want to get rid off) is pretty low. However, when copper cations are precipitated or in any other way removed from the solution, there is still EDTA complex that can release copper. Thus you will have copper present in needed concentration for much longer, than when you simply add copeer sulfate.

At least that's what seems to be logical in this situation.

[fry lover]

Thank you, that's the one of the things i read somewhere, about Copper EDTA lasting longer in the water than Copper Sulphate (i think i've got that right?)

[Borek]

Yes. At least that's what I would expect.