Dosage math help

[Wildreefs]

just want to point out Humblefish and I already spoke about the use of it, however it’s really the only option I have.

I have quick cure from mardel, used it thinking it was 37 percent formalin, turns out it’s not, its 18.5 percent.

Knowing that, in my mind 18.5 percent of say 100 is 18.5. So if I have 100 ml, it’s 18.5 formalin in weight, if I need 37, doubling that dose of 200, would give me 37 formalin.

The product also contains .44 percent malachite green, so would doubling this dose, which will give me .88 of it in weight, be harmful?

Trying to see if I double the dose from .6 or .8ml per gallon, to 1.2 or 1.6 per gallon, if that would yield me to much malachite .


.44 of a percent doesn’t sound like very much

 

[Big G]

@aykwm recommends only using malachite green + formalin as a bath.

https://www.reef2reef.com/threads/medication-compatibility-guide.313491/#post-3862527

 

[Wildreefs]

Understood, but doubling the dose to get the proper formalin amount also yields higher malachite green, from what I am reading so far is no good.

Not sure if it’s too much mg at the end of it

 

[AcroNem]

100% formalin is 37% formaldehyde in methanol and water. So if the medication you're using is 18.5 percent formalin it's about 6.85 percent formaldehyde. To get to a proper dose of 25ppm (at industry standard .1mL/gal) you would need almost 5.5 times as much of what you have. But I see dosage for yours saying .6-.8mL/gal which should give you slightly higher than the proper concentration of standard dosing for 100% formalin already. Doubling that will give you more than 50ppm (it's more than that, I just threw out a number) of formalin, which I wouldn't do in a prolonged bath.

 

[Wildreefs]

100% formalin is 37% formaldehyde in methanol and water. So if the medication you're using is 18.5 percent formalin it's about 6.85 percent formaldehyde. To get to a proper dose of 25ppm (at industry standard .1mL/gal) you would need almost 5.5 times as much of what you have. But I see dosage for yours saying .6-.8mL/gal which should give you slightly higher than the proper concentration of standard dosing for 100% formalin already. Doubling that will give you more than 50ppm (it's more than that, I just threw out a number) of formalin, which I wouldn't do in a prolonged bath.

Thank you, I am still a bit confused .

For what I’ve read on here and abroad, the consensus states to get 37 percent formalin product, and use in dip, (45 minutes on average) at 1 ml per gallon (latest from humble fish states .6 ml per gallon with water temp about 70)

The stuff I have is 18.5 percent , as opposed to the recommended 37%.

Would not doubling it, say from 1 ml per gallon to 2, , give me the same concentration of using 1 ml at 37%?

 

[AcroNem]

Is your medication 18.5 percent formalin, or 18.5 percent formaldehyde? Two quite different levels. For a short bath, yes 1mL/gal of 100% formalin (which is 37% formaldehyde) will give you a 250ppm bath and 30-60 minutes is standard. But if yours is 18.5 percent formalin, it is only 6.85 percent formaldehyde, which is roughly 5.5 times less concentrated than 100% formalin.

 

[Wildreefs]

My understanding is it should be 37 percent, but I have the 18.5 variety, 37 cut in half.

It is the quick cure from mardel

 

[AcroNem]

Okay, sorry I know it's confusing but it's a very important distinction to make, a concentration of Formalin and one of Formaldehyde are very different things.

I finally found on fritz website that quick cure is 18.5% formaldehyde, if that's to be trusted then yes it is half normal formalin concentration. So yes, doubling it from 1mL/gal to 2mL/gal will give you a proper formalin concentration. But as for malachite green I'm not sure if that would be safe. Do you not have time to order pure Formalin?