# Help! Whos good at math?



## Master wilkins (Dec 10, 2012)

I have an outbreak of callamanus worms and picked up some liquid panacur (fenbendazole 10%). I called the vet to ask how much i need to put in the tank and he said 2mg per litre. But i have no math skills whatsoever and cant do the conversion from mg to ml. He told me to go to the pharmacist for the conversion but they didnt seem too confident either. They told me i need to put in 0.02ml per litre of aquarium water. Can anybody confirm this?


To make it fun i can put it in highschool test form haha

Johnny has sick fish. Sarah gave johnny some medication at 10% strength. The directions say he needs 2mg per litre of water. How many ml of the liquid medication does he need per litre of water in the aquarium?


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## Immus21 (Jun 14, 2010)

mg is equal to a ml as far as I know...


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## Bobsidd (Dec 28, 2012)

I think 1g is equal to 1ml for water. Anything more dense would weigh more than 1g per ml. It's probably a fair estimate though.


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## Master wilkins (Dec 10, 2012)

Well okay, but i thought that there was some difference as mg is weight and ml is volume. Even still that still doesnt help as the 2mg value is pure medication, i have a 10% concentration of the liquid. 

Its all very confusing...


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## Immus21 (Jun 14, 2010)

Bobsidd said:


> I think mg is equal to ml for water. Anything more dense would weigh more than 1mg per ml. It's probably a fair estimate though.


I'm out then!


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## Durogity (Jun 10, 2013)

Convert milligram/milliliter - Density Units Conversion says that ml - mg is equal so 2mg/ml x 3.785liters (1gallon)= 7.57 mg/ml per gallon


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## Durogity (Jun 10, 2013)

Did you tell the vet you bought 10%? If do then its 7.57 per gallon, if its based on 100% it'd be 7.57 per ten gallons


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## Bobsidd (Dec 28, 2012)

Actually, isn't it 1 gram, not mg, of water is equal to 1 mL.


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## Durogity (Jun 10, 2013)

According to that conversion site, a gram is .001 of a ml


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## Bobsidd (Dec 28, 2012)

Durogity said:


> According to that conversion site, a gram is .001 of a ml


Wouldn't that mean 1L of water would weigh 1 gram? That doesn't seem right.

I'd say the pharmacist meant 0.02ml per litre of water if they knew you had the 10% concentration.

Here's my reasoning:

2 mg/ litre = 0.002mL/ litre
At 10% concentration, you'd need 10 times as much so,
0.02mL/ litre

I am feeding my son and cooking dinner while writing this, so someone may wish to proofread before you go squirting stuff in your tank.


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## jkcichlid (Apr 21, 2010)

Bobsidd said:


> Wouldn't that mean 1L of water would weigh 1 gram? That doesn't seem right.
> 
> I'd say the pharmacist meant 0.02ml per litre of water if they knew you had the 10% concentration.
> 
> ...


I would say this is correct
A mL of water is one gram, a gram is 0.001 of a L and a mg is 0.001 of a gram


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## Adz1 (Apr 21, 2010)

ask Charles or Patrick at Canadian aquatics.......


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## Foxtail (Mar 14, 2012)

Your 110 gallon tank is around 400 liters... Just multiply by 400 but that would be 800 mg. I used levamisole hcl from patric (mykiss) when I had callamanus worms... Worked awesome.

Sent from my Galaxy Nexus using Tapatalk 2


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## Rockman (May 19, 2013)

Interesting solutions here guys. This is how I do it.

We have a 10% (by weight) stock solution. That's 100,000 ppm. We want 2 mg/l when we're done. 2 mg/l is about equal to 2 ppm. To calculate how much water we need to mix it with, use the equation *F=I x Vi/Vf*, where F is our target final concentration of 2 ppm, I is our initial 10,000 ppm concentration of our stock solution, Vi is the volume of the stock solution we need to add, and Vf is the final volume of the diluted mix (we'll say 1 litre).

Solving for Vi gives us Vi = 2 ppm / 100,000 ppm x 1 L = 0.000002 L, or *0.02 ml of stock solution per litre of tank water*.


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## Master wilkins (Dec 10, 2012)

Rockman said:


> Interesting solutions here guys. This is how I do it.
> 
> We have a 10% (by weight) stock solution. That's 100,000 ppm. We want 2 mg/l when we're done. 2 mg/l is about equal to 2 ppm. To calculate how much water we need to mix it with, use the equation *F=I x Vi/Vf*, where F is our target final concentration of 2 ppm, I is our initial 10,000 ppm concentration of our stock solution, Vi is the volume of the stock solution we need to add, and Vf is the final volume of the diluted mix (we'll say 1 litre).
> 
> Solving for Vi gives us Vi = 2 ppm / 100,000 ppm x 1 L = 0.000002 L, or *0.02 ml of stock solution per litre of tank water*.


I tried to read that... You lost me at ppm... But you sound like you know what you're talking about (or you're just really good at making gibberish sound plausible), so I'm going to go with your agreement with the pharmacist. Thanks everybody for the input, you helped me out a bunch.


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## Bobsidd (Dec 28, 2012)

Master wilkins said:


> I tried to read that... You lost me at ppm... But you sound like you know what you're talking about (or you're just really good at making gibberish sound plausible), so I'm going to go with your agreement with the pharmacist. Thanks everybody for the input, you helped me out a bunch.


Admit it. It was the bold type.


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## davefrombc (Apr 21, 2010)

See people.. You should have paid more attention in math class.. You really do need some of that crap they taught you .. LOL 
I should say tried to teach you 

Bobsidd is correct .


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## Master wilkins (Dec 10, 2012)

Bobsidd said:


> Admit it. It was the bold type.


If it wasn't for the bold type, I never would have known that he was trying to give me an answer! haha!


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