DIY Fluoride

[Randy Holmes-Farley]

Just want to double check the difference between sodium fluoride and potassium fluoride is not relevant for our use? If you have time would love to learn about the differences and why if so thank you.

The fluoride and its counterion (sodium or potassium) are not attached to each other in the liquid supplement bottle, and are not involved with one another in the tank, so it only comes down to adding sodium or potassium as both add ordinary F- ion.

The addition rate of fluoride is likely low enough that potassium elevation is not a big concern, but I see no reason to not use sodium fluoride unless you measured potassium and know it is low. :)

 

[Vested]

The fluoride and its counterion (sodium or potassium) are not attached to each other in the liquid supplement bottle, and are not involved with one another in the tank, so it only comes down to adding sodium or potassium as both add ordinary F- ion.

The addition rate of fluoride is likely low enough that potassium elevation is not a big concern, but I see no reason to not use sodium fluoride unless you measured potassium and know it is low. :)

Awesome thank you, extra cautious diying the elements because of it being in a 1g solution with all the others for captiv8. Appreciate your knowledge as always

 

[Randy Holmes-Farley]

Awesome thank you, extra cautious diying the elements because of it being in a 1g solution with all the others for captiv8. Appreciate your knowledge as always

You’re welcome. The reason it is high is because fluoride is a ppm level component of seawater while many trace elements we dose are ppb level components.

 

[Biff0rz]

To those of you mixing your own NaF, what PPE are you using? I want to do this but I also want to do it right.

 

[Isaac Alves]

The amount to can safely dose is up to NSW each time. If you don't know what that is on a daily basis, because you do not know the daily demand (if any), then I would not be able to suggest a dose.

The recipe I give there is

If you dissolve 10 grams in 1 L, then it is 10 mg/mL NaF and it takes 22 mL of that solution to boost 100 L by 1 mg/L F.

If you want to raise 200 gallons (757 L) by 0.7 mg/L (0.8 to 1.5 mg/L) then you will need 117 mL.

Out of curiosity, how long does 10 grams of sodium fluoride take to dissolve in 1l of RoDi water?

 

[Isaac Alves]

To those of you mixing your own NaF, what PPE are you using? I want to do this but I also want to do it right.

I used gloves, eye protection and a mask. I used a long lab spoon to pull the powder carefully onto the scale.

I hope that was enough :grimacing-face:

 

[Isaac Alves]

Out of curiosity, how long does 10 grams of sodium fluoride take to dissolve in 1l of RoDi water?

Hmmmm realize I’m stirring it up in a glass flask. Is that an issue with mixing? Thought I’d stir it up here then pour into an HDPE sealed bottle.

 

[USMA36]

Out of curiosity, how long does 10 grams of sodium fluoride take to dissolve in 1l of RoDi water?

I’m curious as well. I just tried mixing up my own batch this morning using the loudwolf sodium flouride. 1.1 grams in 500ml of water and I’m having the same issue of it not mixing great. I’m using a magnetic stirrer for the last few minutes. Does water temp affect solubility? My water is probably 45° F or so.

 

[Randy Holmes-Farley]

I’m curious as well. I just tried mixing up my own batch this morning using the loudwolf sodium flouride. 1.1 grams in 500ml of water and I’m having the same issue of it not mixing great. I’m using a magnetic stirrer for the last few minutes. Does water temp affect solubility? My water is probably 45° F or so.

Chemicals can often dissolve faster at higher temps, even those with lower solubility in warm water. In this case, the solubility limit of NaF is far higher than your solution, and increases a small amount with raised temp. I'd just let it stir overnight.

If it is not 90+% dissolved by morning, I suspect a problem.

This is in 0 ppm TDS RO/DI, right?

 

[USMA36]

Chemicals can often dissolve faster at higher temps, even those with lower solubility in warm water. In this case, the solubility limit of NaF is far higher than your solution, and increases a small amount with raised temp. I'd just let it stir overnight.

If it is not 90+% dissolved by morning, I suspect a problem.

This is in 0 ppm TDS RO/DI, right?

Thank you! Yes 0 tds. It seems to have mixed. I should add that I was mixing it outside in 18° temps to avoid any possible fumes so my 45° starting temp was probably much closer to freezing after an hour.

 

[Randy Holmes-Farley]

I actually thought you meant warmed to 45 C. lol

Glad it is working now.

 

[Ben Mccue]

The amount to can safely dose is up to NSW each time. If you don't know what that is on a daily basis, because you do not know the daily demand (if any), then I would not be able to suggest a dose.

The recipe I give there is

If you dissolve 10 grams in 1 L, then it is 10 mg/mL NaF and it takes 22 mL of that solution to boost 100 L by 1 mg/L F.

If you want to raise 200 gallons (757 L) by 0.7 mg/L (0.8 to 1.5 mg/L) then you will need 117 mL.

*edited for bad math...I bought the sodium fluoride linked above. Using the MS classic calculator it looks like they have it mixed where 100 ml of their solution raises 100 liters 1 mgl. So for your recipe that would be 10 grams in 1000ml for 22ml dose, theirs 10 grams in 4544 ml for a 100ml dose. Is my math correct here? $20 a half liter of their solution is pretty insane to me considering how much you need with a large tank (if you do water changes). my simple math was their dose 100ml /your dose 22ml*1000ml.

 

[Randy Holmes-Farley]

*edited for bad math...I bought the sodium fluoride linked above. Using the MS classic calculator it looks like they have it mixed where 100 ml of their solution raises 100 liters 1 mgl. So for your recipe that would be 10 grams in 1000ml for 22ml dose, theirs 10 grams in 4544 ml for a 100ml dose. Is my math correct here? $20 a half liter of their solution is pretty insane to me considering how much you need with a large tank (if you do water changes). my simple math was their dose 100ml /your dose 22ml*1000ml.

If you use this recipe:

NaF is 45% fluoride by weight, so to add 1 mg/L to 100 liters takes
(1 mg/L x 100 L ) / 0.45 = 222 mg, or 0.2 grams.
You can dissolve up to about 30 grams in a litter of RO/DI.
If you dissolve 10 grams in 1 L, then it is 10 mg/mL NaF and it takes 22 mL of that solution to boost 100 L by 1 mg/L F.

then that DIY is 4.5 times as potent as the Moonshine product mentioned, though I cannot confirm it's potency beyond reading that calculator picture.

 

[Ben Mccue]

So.. that looks like 8.33 grams per gallon to match MS strength. And out of a 1lb bottle you can get 54.4 Gallons of solution for $35. so that would be 412 half liter bottles of the same fluid which would cost $8,240 retail buying MS. I think i did all that math correct.

 

[Biff0rz]

So.. that looks like 8.33 grams per gallon to match MS strength. And out of a 1lb bottle you can get 54.4 Gallons of solution for $35. so that would be 412 half liter bottles of the same fluid which would cost $8,240 retail buying MS. I think i did all that math correct.

yes, MS is a ripoff

 

[Ben Mccue]

Yeah, concept is sound. Test and dose individual elements as needed. But the prices are pretty insane on some of them fluoride especially. I needed 325ml last icp test. I'm already getting tired of $60 for icp followed by needing $80 of "correctional" solutions.

 

[Merge_595]

Very helpful & right on time. Just put Flouride on a doser while thinking to myself..man this will be expensive!

 

[Ben Mccue]

I'm about to mix my first batch of diy flouride for my new tank, 250 gallons running volume. I used 200 gallons of fresh fritz mix and 50 gallons from the old 180. I would need 938 ml ($40) of MS flouride to get the 200 gallons of fresh fritz up to target. I sent an an icp for fresh fritz mix at 35ppt a while ago so that's my reference.

 

[WhatCouldGoWrong71]

Thank you! Yes 0 tds. It seems to have mixed. I should add that I was mixing it outside in 18° temps to avoid any possible fumes so my 45° starting temp was probably much closer to freezing after an hour.

Thanks for the help with this. My RODI stores at 65-70 ish degrees. I didn’t notice any issues mixing this.

 

[tapeworm123]

@Randy Holmes-Farley I have the RM Flouride how many ML’S do I need to dose to go from .76 mg/L to 1.3 mg/l 120 gallons of water?