How I Mix Sodium Hydroxide

[Miami Reef]

This thread is for the general discussion of the Article How I Mix Sodium Hydroxide (V2 – Updated Method). Please add to the discussion here.

 

[JHSteepat]

Please someone correct me if I'm wrong.

It's been many years since I worked in a research lab, but I am not sure adding water to NaOH is advisable. I recall always adding the solid pellets to water.

 

[bubbgee]

I used an old glass vase and after adding the powder, add RODI slowly. SLOWLY. It heats up read bad if you pour out water so use a glass container than a plastic one. For storage, make sure it’s hpde.

I did not read the notes before because I got too excited and the water bottle melted lol. I’ve been better since.

 

[Miami Reef]

Please someone correct me if I'm wrong.

It's been many years since I worked in a research lab, but I am not sure adding water to NaOH is advisable. I recall always adding the solid pellets to water.

You’re correct. Standard chemistry practice is to never add water to solids.

I’ve been doing this for years, and there’s no harmful reaction or explosion. Most solids will remain on the bottom until you invert it. It will quickly dissolve.

The heat is dispersed as you add water to it.

 

[Miami Reef]

I used an old glass vase and after adding the powder, add RODI slowly. SLOWLY. It heats up read bad if you pour out water so use a glass container than a plastic one. For storage, make sure it’s hpde.

I did not read the notes before because I got too excited and the water bottle melted lol. I’ve been better since.

In my experience, glass gets VERY hot when adding sodium hydroxide, even smaller, diluted amounts.

I have not had this issue with the HDPE containers.

 

[Randy Holmes-Farley Verified Community Expert]

The issue would come about if the water addition takes significant time, allowing a small amount of water to get unusually hot. If the water is added all at once it’s not an issue.

 

[Miami Reef]

The issue would come about if the water addition takes significant time, allowing a small amount of water to get unusually hot. If the water is added all at once it’s not an issue.

Yes. I add it rapidly. I have a separate gallon jug prefilled with RO/DI. I can definitely add that note to the tutorial.

 

[JHSteepat]

The issue would come about if the water addition takes significant time, allowing a small amount of water to get unusually hot. If the water is added all at once it’s not an issue.

That's what I figured, but felt it was significant enough issue to raise before someone hurts themselves or just makes a mess. I never did it in that order.

 

[JHSteepat]

Yes. I add it rapidly. I have a separate gallon jug prefilled with RO/DI. I can definitely add that note to the tutorial.

You might want to add rapidly, taking care not to splash the liquid, or something like that. Sorry, I'm an attorney.

 

[Futuretotm]

How to burn your face and strip the pain from your apple watch:
I dose NAOH for the alk component, I usually prepare multiple one gallon jugs.

I have FIVE gallon jugs waiting, three have RODI in them, two just have a little bit of RODI.
I prepare the three with full RODI... give em a shake to mix .... no problems
I "prepare" the other two with minimal RODI thinking I'd add more RODI later...... I throw the NAOH powder in there, give em a shake (habit)

BOOM cap comes off, burns my face and strips the paint off my watch, takes of paint from the wall paintings, the wall itself aswell.....

this was two years ago.

Kids, dont take shortcuts!

 

[Miami Reef]

I still feel that the method I outlined, while going against traditional chemistry protocol, was explained with care and enough caution for people to understand the risks. I’ve personally used it safely for years, and I believe it’s manageable for experienced hobbyists if done carefully and with the right context.


That said, I understand that not everyone will agree with the approach, and I never want to encourage something that could harm someone if misunderstood or poorly executed.


The only reason I shared this is because there aren’t many detailed tutorials out there on mixing sodium hydroxide, and I thought it might help others who were curious about how I do it. I also wrote a previous tutorial that does follow the standard “add NaOH to water” method — and maybe that’s the one that should remain as the primary reference for safety.


@Randy Holmes-Farley If you feel like tutorial causes more harm than good, you can have it deleted.


I just want the right information to be available and for people to stay safe, whichever method they choose.

 

[Randy Holmes-Farley Verified Community Expert]

I think a procedure to add 75% of the water at once is fine.

Folks should always be very careful with this material, and others we use. Safety glasses are a must, IMO, when handling high or low pH solutions.

 

[Miami Reef]

I think a procedure to add 75% of the water at once is fine.

Folks should always be very careful with this material, and others we use. Safety glasses are a must, IMO, when handling high or low pH solutions.

Thanks for the input, Randy. I went ahead and updated the article to emphasize the importance of using safety goggles when handling high pH solutions. I appreciate you taking the time to look it over.

 

[EliMelly]

Is this the right place for someone to teach me how to cook meth?

All jokes aside great write up.

#chemistry

 

[Cow]

Around how many mL are ya'll dosing at that 283g per gallon concentration? I've seen pH dosers for sale on FB marketplace and am curious if I'll need something like that to keep from accidentally raising pH too high. I have an Apex and am going to try and use a Jecod pump.

 

[Randy Holmes-Farley Verified Community Expert]

Around how many mL are ya'll dosing at that 283g per gallon concentration? I've seen pH dosers for sale on FB marketplace and am curious if I'll need something like that to keep from accidentally raising pH too high. I have an Apex and am going to try and use a Jecod pump.

It, of course, depends on tank size and alk demand, but you can use this calculator and the entry for Randy Recipe#1 to see how much you'd dose:

https://reef.diesyst.com/chemcalcnew.html
For example, a demand of 2 dKH per day in 100 gallons water volume would need 142 mL per day.

Not sure what a pH doser is, but rarely do folks get pH too high.

 

[Val Shebeko]

This thread is for the general discussion of the Article How I Mix Sodium Hydroxide (V2 – Updated Method). Please add to the discussion here.

Ok, tried to raise ph with soda ash —- nada

With pulling air through soda lime ~~~ nada



Tried calcium hydroxide - need vast quantities



Tried sodium hydroxide ~~ 283 grams to a gallon of rodi and through an abundance of caution made a 30 % solution and with a Milwaukee pH Controller controlling a dosing pump and HOLY MOTHER MOTHER OF GOD the pH rose miraculously as did the dKH.



Is there a way to control the hardness ?|

 

[KStatefan]

Dose to alk demand not to a pH number.

 

[Randy Holmes-Farley Verified Community Expert]

if you mean a 30% solution by mass, I do not recommend that at all. If you mean 30% of the recipe in this thread, that’s fine.

This recipe has the exact same alk potency as my soda ash recipe (BRS also uses it) and one can use any of a number of online calculators to determine the alk added.