DIY Trace liquid: need help on formula

[acro_lover]

You’re welcome.

Happy Reefing. :)

Looks good. :)

Back to the Selenomethionine :) Hi,
i managed to find 200ug tablets. They advertise no fillers or bulking agents in the tablets, so i hope is good enough.
Can you please check my math as i am really worried?
I want to dose 0.02ug/L a day.
So if i dissolve i tablet of 200ug in 1L of ro water, that would give me 200ug/L.
200ug/0.02ug= 10 000
1000ml / 10 000= 0.1
so if i dose 0.1ml of that liquid that would give me 0.02ug/L
SInce my tank is 900L
0.1ml x 900L = 90ml
So i if i dose 90ml of that liquid (1 capsule 200ug dissoved in 1L of ro water) that would give me concentration of 0.02ug/L for my 900L aquarium.
Is the above correct?

 

[acro_lover]

Hi, anyone can check my calculations above?

 

[Randy Holmes-Farley Verified Community Expert]

Correct. :)

So if i dissolve i tablet of 200ug in 1L of ro water, that would give me 200ug/L.

That 200 ug/L is 0.2 ug/mL

If you have 900 L and want 0.02 ug/L per day, then you add

900 L x 0.02 ug/l/day = 18 ug/day

Thus, you need 18 ug/0.2 ug/mL = 90 ml per day.

 

[acro_lover]

Correct. :)

So if i dissolve i tablet of 200ug in 1L of ro water, that would give me 200ug/L.

That 200 ug/L is 0.2 ug/mL

If you have 900 L and want 0.02 ug/L per day, then you add

900 L x 0.02 ug/l/day = 18 ug/day

Thus, you need 18 ug/0.2 ug/mL = 90 ml per day.

Thank you so much for checking.
Whenever you have a second, can you please check my math for the chromium:
I want to dose Chromium(III) chloride hexahydrate at a daily rate of 0.02ug/L
Tank is 900L

CrCL3.6H2O must be 19.5% chromium by weight.

Dissolve 1 g in 1 L RO/DI, and the concentration is 195 mg/L, or 195 ug/mL.

Adding 1 mL (195 ug) to 100 L of aquarium water boosts chromium by 1.95 ug/L.
If I dissolve 90mg in 1L, 1ml added to 900L of that solution should give me 0.02ug/L.
Is that correct?

 

[acro_lover]

Anyone able to confirm my calculations? Many thanks

 

[Randy Holmes-Farley Verified Community Expert]

Yes, that is correct. :)

 

[acro_lover]

Yes, that is correct. :)

Yes, that is correct. :)

Thank you much Randy. Happy Reefkeeping:)

 

[acro_lover]

Correct. :)

So if i dissolve i tablet of 200ug in 1L of ro water, that would give me 200ug/L.

That 200 ug/L is 0.2 ug/mL

If you have 900 L and want 0.02 ug/L per day, then you add

900 L x 0.02 ug/l/day = 18 ug/day

Thus, you need 18 ug/0.2 ug/mL = 90 ml per day.

Hi, i have mixed my Selenomethionine tablets but wanted to make the solution very concentrated so i can dose smaller amounts with a syringe daily. I was also hoping that the more concentrated the solution is, the less chance to build up bacteria. Sterilized my glass bottle and dissolved 64 tablets (200ug each) in 0.5L of distilled water. That way i can dose 0.7ml to 900L aquarium for concentration 02ug/L a day. According the google Selenomethionine is highly soluble ( to about 50ug/ml) and it mixes clear. My one is cloudy. Not a lot, like milk, but pretty cloudy. I believe thats due to the concentration, but I am wrong? Am i missing something? Also, the manufacturer of the tablets states that there aren't any filler in them. Whats your experience with mixing Selenomethionine. Do i have to be worried or since this is natural amino acid, its normal to mix cloudy at high concentration?

 

[Randy Holmes-Farley Verified Community Expert]

Hi, i have mixed my Selenomethionine tablets but wanted to make the solution very concentrated so i can dose smaller amounts with a syringe daily. I was also hoping that the more concentrated the solution is, the less chance to build up bacteria. Sterilized my glass bottle and dissolved 64 tablets (200ug each) in 0.5L of distilled water. That way i can dose 0.7ml to 900L aquarium for concentration 02ug/L a day. According the google Selenomethionine is highly soluble ( to about 50ug/ml) and it mixes clear. My one is cloudy. Not a lot, like milk, but pretty cloudy. I believe thats due to the concentration, but I am wrong? Am i missing something? Also, the manufacturer of the tablets states that there aren't any filler in them. Whats your experience with mixing Selenomethionine. Do i have to be worried or since this is natural amino acid, its normal to mix cloudy at high concentration?

Did you open the capsule and pour out the components, or did you dissolve the whole thing? The capsule material may contribute to cloudiness.

 

[acro_lover]

Did you open the capsule and pour out the components, or did you dissolve the whole thing? The capsule material may contribute to cloudiness.

dosed only the powder. Carefully opened the capsules and poured only the powder. Did that with gloves and the bottle was sterilized, boiler for 15 min.

 

[Randy Holmes-Farley Verified Community Expert]

dosed only the powder. Carefully opened the capsules and poured only the powder. Did that with gloves and the bottle was sterilized, boiler for 15 min.

You are fairly close to what I see as the solubility limit. I never tried to make such a solution. Maybe there’s a less soluble impurity, or maybe it needs a little acid or base to increase the solubility. Or maybe just warming may help.

 

[acro_lover]

i will try with a little bit of warming first or just dilute it further. Will update here so everyone knows in case they decide to use DIY selenium. Thank you for checking it.
Got stuck a bit with my DIY Boron.
I bought:
Sodium Tretraborate Anhydrous 98%
I cant find molar mass for anhydrous at wikipedia. The web page i bought from says molar mass is 201.21 g/mol. I wanted to double check that. Do you know where else i can check?
Assuming is 202.21, then Sodium Tetraborate is only 5% boron by weight?
10.806 / 201.21 x 100= 5.37%

Something must be wrong here, is it?

Then i found this in the DIY Chemistry Archive, which is far away from my calculations:

"for increase de Boron
0.88 grams of borax (sodium borate 10H2O ) increases the boron concentration in 100 liters of water by 1 ppm.
this recipe is not mine but the author is trustworthy
that recipe is the responsibility of those who use"

 

[Randy Holmes-Farley Verified Community Expert]

Sodium tetraborate is Na2 B4O7, with a molecular weight of 201.2 g/mole

Sodium Borate

Sodium Borate | Na2B4O7 or B4Na2O7 | CID 10219853 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

pubchem.ncbi.nlm.nih.gov

Since it contains 4 borons, it is 4x 10.8/201.2 x 100% =0.215 21.5% boron

 

[acro_lover]

OMG, such a shame ...thank you for opening my eyes. Many thanks for the correction.

In that case:
Sodium Tatraborate is 21.5% boron by weight, then:


Dissolve 100 g in 1 L RO/DI, and the concentration is 21500 mg/L, or 21500 ug/mL.

Adding 10 mL (21500 ug) to 100 L of aquarium water boosts cobalt by 2150 ug/L, or 2.15mg/L

Does this look correct?

 

[Randy Holmes-Farley Verified Community Expert]

OMG, such a shame ...thank you for opening my eyes. Many thanks for the correction.

In that case:
Sodium Tatraborate is 21.5% boron by weight, then:


Dissolve 100 g in 1 L RO/DI, and the concentration is 21500 mg/L, or 21500 ug/mL.

Adding 10 mL (21500 ug) to 100 L of aquarium water boosts cobalt by 2150 ug/L, or 2.15mg/L

Does this look correct?

Yes, although you lost a digit in the 10 mL (21500 ug). Should be (10 mL is 215000 ug)

 

[acro_lover]

Yes, although you lost a digit in the 10 mL (21500 ug). Should be (10 mL is 215000 ug)

Thank you for the correction and thank you for checking my calculations. The more i work and read for these chemicals the more i am in love with the chemistry and weirdly i used to hate it at high school :) :) Thank you @Randy Holmes-Farley for all your help.

Can i pls have your opinion on the iron sulfate? I've dissolved iron(II)sulfate heptahydrate in water, but a partially large amount of yellowish brown precipitate have been formed in my bottle (bottle was boiled for 15min and used distilled water). I am adding 50mg in 0.5L ( at room temperature, about 20C), which is far away from max solubility. I thought the FeSO4 i bought is not good quality and bought another batch from different webpage. The new one is 99% ACS reagent quality. However, it mixes the same- with lots of yellowish brown precipitate. What your experience with mixing FeSO4? Is it simply not fully dissolved or I am missing something?

 

[Randy Holmes-Farley Verified Community Expert]

You’re welcome. Glad you like chemistry!

The issue with the iron is probably some air oxidation to ferric iron, Fe+++, from the ferrous, Fe++, in the bottle. Ferric is far less soluble and precipitates as iron oxide/hydroxide, like GFO.

Aside from depleting the potency, that’s no concern. Using a chelated form, such as ferrous gluconate, may keep even the ferric iron in solution.

 

[acro_lover]

You’re welcome. Glad you like chemistry!

The issue with the iron is probably some air oxidation to ferric iron, Fe+++, from the ferrous, Fe++, in the bottle. Ferric is far less soluble and precipitates as iron oxide/hydroxide, like GFO.

Aside from depleting the potency, that’s no concern. Using a chelated form, such as ferrous gluconate, may keep even the ferric iron in solution.

Thanks for your replay.
I will try next time the ferrous gluconate. For now i will just be using the iron sulfate. I will adjust dosage according to ICP`s so a bit less potent - its not a major concern.

i know you are not a fan of dosing barium, but would you please check my calculations whenever you a have a second:

Barium Chloride Dihydrate
Barium chloride must be 56% Barium by weight:
If I dissolve 10 g in 1L water the concentration is 5600 mg/L, or 5600 ug/mL.

Adding 1 mL (5600 ug) to 100 L of aquarium water boosts barium by 56 ug/L.

Is that correct? Have a missed something?

 

[Randy Holmes-Farley Verified Community Expert]

Thst looks correct!

 

[acro_lover]

Thst looks correct!

Happy Easter!
Am i right to assume that if i dose selenomethionine, it wont show up on icp since is organic? Thanks