Badman's Tropical Fish

All-Water Boards => Other Aquatic Pets => Topic started by: Jake on March 21, 2014, 10:43:40 PM

Title: Fertilizing a Shrimp Tank
Post by: Jake on March 21, 2014, 10:43:40 PM
Is it OK to add Flourish to a shrimp tank? According to the label, it contains 0.0001% water soluble copper. I know this is a very small amount, but I also know that shrimp are very sensitive to copper. Does anyone have experience with this? Thanks in advance!

Title: Re: Fertilizing a Shrimp Tank
Post by: Dylan on March 22, 2014, 09:40:44 AM
Ive been adding flourish to my shrimp tank for a few months and haven't noticed any problems. They are RCS however so they're pretty hardy. If you're dealing with higher end shrimp like crystal reds, I'm not exactly sure if that amount would have an effect on them or not.

Title: Re: Fertilizing a Shrimp Tank
Post by: Zapins on March 23, 2014, 01:41:00 PM
Jake, I answered a similar question on APC a few weeks back I've copy & pasted it here for you since I think it also answers your question.


Quote from: Zapins
I'm not a SeaChem representative but I can probably answer your question.

Copper sulfate is used as medication and can be harmful to shrimp when the concentration is high enough. That said, you can use copper sulfate as a source of copper at very low concentrations which is what flourish does (and so do nearly all other micro mixes on the market).

Copper toxicity (the LD50) for cherry shrimp is 0.37 ppm. If used correctly any copper based fertilizer you put in your tank should never get anywhere close to that level even when liberally over dosing (even 10-100x recommend dose levels).

To show you what I mean here is an example:

When using flourish comprehensive to get 0.5 ppm iron (the recommended EI iron dose) you add 0.0002 ppm copper from copper sulfate. This is from 53 mL of flourish comprehensive in a 90g tank. You'd have to add 1850x the recommended dose to reach 0.37 ppm (toxic level), that is equivalent to about 26 gallons of Flourish Comprehensive in a 90g tank.

If you'd like to figure out how much copper from copper sulfate you are adding with flourish or any other micro mix, check out ( it will show you every micro concentration in whatever sized tank and with all recommended dosing guides.

Basically the answer to your question is, there is absolutely NO risk to your shrimp from Flourish Comprehensive.

Title: Re: Fertilizing a Shrimp Tank
Post by: Jake on March 23, 2014, 10:21:52 PM
Great news! Thank you so much! I just wanted to be sure.

Potentially dumb follow up question though. The copper that is added is taken up by the plants correct? So if all of my plants died overnight, as they were decomposed the copper would be released back into the tank right? So I just have to make sure that I don't kill all of my plants! Is this logic sound?

Thanks for the responses!

Title: Re: Fertilizing a Shrimp Tank
Post by: Zapins on March 23, 2014, 11:41:48 PM
Plants are about as tolerant of copper as shrimp are depending on the species.

It is unlikely that your plants would die from copper toxicity unless you were adding copper sulfate medication or had naturally high copper tap levels.

Also, not all copper is harmful, only free ionic copper is bad for shrimp/plants. If the copper is chelated or bound up in organic molecules like those that would be found in decaying plants the copper is 100's if not 1000's of times safer. Also, plants don't contain huge amounts of copper, so even if all your plants died, it wouldn't be the copper that killed your shrimp - much more likely to be ammonia from rotting plants!

Title: Re: Fertilizing a Shrimp Tank
Post by: Jake on March 25, 2014, 11:04:03 PM
Fantastic. Thank you so much!!