# Potassium and shrimp



## Phil Edwards (Jan 22, 2004)

Hey folks,

I've had terrible, murderous, luck with shrimp ever since I started keeping them. Sometimes they'd be fine for a while then suddenly die. Other times they'd die as soon as I put them in the tank even though they've always been well enough established to nix ammonia/ammonium problems.

Lately I read somewhere that potassium may also be lethal to shrimp in high enough doses. I usually run my tanks K-rich and think that may be why I've only been able to keep them sporadically. Sometimes the tanks are low enough, sometimes they're too rich. 

Does anyone have a figure on what potassium levels are considered toxic to shrimp? If I can get over this hurdle it'll be a major milestone for me. Just like keeping mosses. >< 

Thanks!
Phil


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## bs6749 (Dec 23, 2007)

How do you know it's the potassium that is hurting the shrimp? Also, what form is the potassium in when you are dosing? Commonly, it's potassium nitrate that is used for planted tanks and in that case I'm guessing that your shrimp all died because of high nitrates, not potassium.


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## JohnPaul (Aug 28, 2006)

bs6749 said:


> How do you know it's the potassium that is hurting the shrimp? Also, what form is the potassium in when you are dosing? Commonly, it's potassium nitrate that is used for planted tanks and in that case I'm guessing that your shrimp all died because of high nitrates, not potassium.


People looking to explicitly dose potassium usually (often at least) use potassium sulfate (for the very reason you state--so they can get potassium into their tanks without increasing nitrates). Those who need both potassium and nitrates will typically dose potassium nitrate, perhaps with some additional potassium sulfate as needed.


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## Phil Edwards (Jan 22, 2004)

bs6749,

I use potassium sulfate to target suppliment potassium. I'm not 100% sure it's high potassium levels that kill my shrimp but as of right now it's my best guess. I've been able to rule out copper, ammonia, nitrate, and pH so far with pretty high confidence. When I saw somewhere (I can't remember exactly) that potassium may also be toxic at high levels it seemed plausable to me. Potassium's been one of the nutrients I haven't been terribly strict about dosing. I'll dose here and there as I feel my plants need it. Sometimes it was a lot, sometimes it was a little, I really can't say. I never really paid much attention because it's not something that negatively affected my plants and fish and I was always looking at something else as being the cause of shrimp death. So now I'm looking at potassium as a potential toxin and am curious about what levels people have seen or heard of being toxic to shrimp.

Regards,
Phil


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## JohnPaul (Aug 28, 2006)

I'm pretty sure API (and probably other companies as well) make a potassium test. Might want to pick it up and see what your readings are.

My dwarf shrimp tank I dose only very low levels of potassium (less than 10 ppm). I do have a community fish tank with potassium dosed at around 20 ppm and my amano and ghost shrimps don't seem to mind, but I don't have any of the true dwarf species in there.


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