Hikari Wafers and shrimp question

[Vod]

Hello, I have been feeding my plecos Hikari wafers, and while looking over the ingredients, it says copper sulfate. I have a bunch of shrimp in the tank and copper is toxic to invertebrates, but so far it doesn't seem to affect the shrimp as far as I can tell. Anyone have any long term use of this food with shrimp in the tank?

[nabokovfan87]

I don't have any issues with them with amanos. A lot of people use them for snails and shrimp.

Interesting.

[Remi de Groot]

To much copper will kill shrimps but no copper at all will kill shrimps as well...

I kind of knew this but didn't know how it worked exactly, so did a little google search and got this article:
https://aquariumbreeder.com/how-copper-affects-dwarf-shrimp/

[Lennie]

The opinion on this topic seems to be controversial in general. Some people avoid anything that has copper sulfate, while others think it being listed at the end in some fish food clearly shows the amount in the food is so minimal, and even snails and shrimp needs to eat the minimal amount for a good life. I personally feed  NLS thera A+, hikari algae wafers and crab cuisine to my community tank with many other fish food that contains it where I keep nerites, mts, rabbit snails and orange sakuras. Haven’t faced any problems personally. I even dose seachem flourish and it has a very tiny bit of copper in it, still never faced any issues.

It comes to your own decision on this one I guess, Maybe others may share their own experience too. 
 

But aquarium coop sells crab cuisine for snails too if I am not wrong, So that strengthens my trust on feeding it. They even have it it their shrimp cuisine right?

[Flumpweesel]

It's in my shrimp food and my shrimp only started breeding when I moved to this stuff so they certainly seem happy on it.

I think trace elements will be in anything you try

[Cinnebuns]

Yes copper is toxic to inverts. No copper sulfate in fish food will not kill them. They actually REQUIRE a certain level of copper in their blood to survive. 

I don't have the specifics on this because it's 7am and I haven't slept yet but someone once did the math. If you feed fish food containing copper sulfate into a tank in a very large amount it would take approximately 1 year without any water changes for the copper in the tank to reach toxic levels for inverts. 

So, is the copper sulfate toxic?  Technically yes. Will it harm your shrimp?  Doubtful. Just be aware of it. 

Generally when they say to avoid copper they are meaning a copper pipe carrying water or the copper contained in meds. The copper sulfate in foods is just not to the levels where it's an issue. 

Edited January 13 by Cinnebuns

[Guppysnail]

All things need some copper. I use the hikari wafers in many tanks with neocaridina shrimp and have never issues. 

[Rube_Goldfish]

Crustacean blood is copper-based hemocyanin rather than iron-based hemoglobin:

"There are three components that can be present in crustacean blood, including (1) hemolymph – ‘colorless’ blood that is nutrient carrier component of blood; it also may carry some oxygen, and is involved in clotting; (2) hemocyanin – a true copper-based pigment that carries oxygen found in developed Crustacea; (3) and hemoglobin – a true iron-based pigment found in underdeveloped Crustacea. Most species have hemocyanin in their blood (Joel, 2013; Urich, 1994)."

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/crustacea

So I guess it's one of those "the dose makes the poison" things.

[Vod]

Thanks for all the replies.

 

I figured it should be safe, since they seem to be doing ok, and eat the wafers just fine, but wanted more opinions on it. Seems like any buildup of copper in the water from the food, should be removed with water changes.