Black gravel dangerous to RCS??

A few days ago I added some RCS in my cycled 7g tank but after a day or two all of them died :/
My water parameters were fine before adding them and stayed fine after that, so I guess they weren't killed by it.
I know that copper is lethal to them but I still do not have a test for that so copper is a suspect ......but today I was in a fish store and longing at the shrimp tank, the assistant there asked me if I wanted some and explained her what happened with my shrimps .... So she asked me if I have black gravel in my tank (I do, natural not dyed) cause it is loaded with heavy metals and it kills all invertebrates! She said she keeps shrimps herself and she knows etc etc .....
It is the first time I hear something like that and was wondering if it is true ??

 

I have 2 bamboo shrimp in my tank with the "painted" black gravel and have had no problems.

I think she just wanted to sell you some shrimp and gravel to make more money

 

load of bull if it is aquarium gravel it has just as much as any other color.

 

That is a crock of cheese. I have my RCS in a tank with black gravel and I know a lot of other people do too. I've had mine for months with only one death. Trust me, it had nothing to do with the gravel.

 

I have black sand with my RCS...they are fine.

How long has your tank been cycled?

I would say it has to be your water parameters, maybe a pH, temp flux?

 

I have a large colony of RCS that I've had on black gravel for over a year.

 

Thanks for the answers! I am relieved since I just bought a 33gal tank in which I hope after some months to try my luck again with RCS and was planning to use black sand.

As for my first RCSs, they were in their own cycled ~ 6gal tank, the temperature in there goes from 24 to 25.5, the heater doesn't let it drop below 24 but when the lights are one it can get up to 25.5. The water ph is 7.5.....the shrimps came by post, so maybe to stressed ? maybe I made something wrong since my experience with shrimps is close to null...anyway I have a few months to get ready and learn as much as I can before trying again with them.

again thanks a lot

 

Thanks for the answers! I am relieved since I just bought a 33gal tank in which I hope after some months to try my luck again with RCS and was planning to use black sand.

As for my first RCSs, they were in their own cycled ~ 6gal tank, the temperature in there goes from 24 to 25.5, the heater doesn't let it drop below 24 but when the lights are one it can get up to 25.5. The water ph is 7.5.....the shrimps came by post, so maybe to stressed ? maybe I made something wrong since my experience with shrimps is close to null...anyway I have a few months to get ready and learn as much as I can before trying again with them.

again thanks a lot

I use black gravel as well and my shrimps are fine, so like others said; that shouldn't be a problem. Did you test your water post-mortem? There could've been a sudden ammonia/nitrite spike for whatever reason.

Or you could've been unlucky and got a bad batch of shrimp from the site/dealer/breeder? Some sites/dealers offer something like a one or two day guarantee after delivery to attract customers that their stock sent is healthy and not overly stressed during transit. Might be worth checking on the Postage and Delivery conditions.

Out of curiousity, which site (if you did use one) did you purchase them from? If you could PM it to me, would be great.

 

I use black gravel as well and my shrimps are fine, so like others said; that shouldn't be a problem. Did you test your water post-mortem? There could've been a sudden ammonia/nitrite spike for whatever reason.

Or you could've been unlucky and got a bad batch of shrimp from the site/dealer/breeder? Some sites/dealers offer something like a one or two day guarantee after delivery to attract customers that their stock sent is healthy and not overly stressed during transit. Might be worth checking on the Postage and Delivery conditions.

Out of curiousity, which site (if you did use one) did you purchase them from? If you could PM it to me, would be great.

I have tested the water before introducing them and it was fine and then tested again after 2 days, so yes maybe a sudden spike may have been the reason. I have ordered a copper test too so in a couple of days I will know about that too.

He was a breeder in ebay, his ratings were perfect....but you never know. I can't find the PM button...so I guess the forum does not allow me to send personal messages yet.

 

You can't PM until you have 50 posts.

 

I have tested the water before introducing them and it was fine and then tested again after 2 days, so yes maybe a sudden spike may have been the reason. I have ordered a copper test too so in a couple of days I will know about that too.

He was a breeder in ebay, his ratings were perfect....but you never know. I can't find the PM button...so I guess the forum does not allow me to send personal messages yet.

How did you acclimate them?

 

How did you acclimate them?

floated the bag for around an hour in the tank and then was adding a bit of tank water every 10-15 mins for another hour or so.