Differences between Sodium Phosphate Dibasic, Monobasic, and Trisodium Phosphate?

Randy Holmes-Farley · Jun 8, 2022

Trisodium phosphate is, by itself or in combination with other agents, a good cleaning agent. That does not make it any less suitable for use in a reef tank if adequately pure. It raises the pH a fair bit, which is partly why it works as a cleaner, making many chemicals more soluble at high pH.

Sodium hydroxide is used in drain openers and oven cleaners and yet is a fine alk supplement.

I do not recommend ANY ungraded additives for supplementing N and P in a reef tank. The one you show is ungraded and may not be pure. But food grade trisodium phosphate will not be much different than dosing food grade di or monosodium phosphate.

gbroadbridge · Jun 8, 2022

Reefahholic said:
One quick question…why would TSP be recommended over other choices if it’s a heavy duty cleaner?

When I had to dose a high volume of that stuff, I really observed a cleaner type effect in the tank. Rocks, glass, etc…didn’t grow any kind of algae and when I scrapped the glass, it was hard to drag the magnet across almost like it was extra clean. The rocks were also turning nearly black. Extremely dark brown. No algae was forming or anything. Not even a light dusting on the glass as you would expect for nearly over dosing TSP trying to get a PO4 reading. Definitely will never dose it again. I’m very curious as to the other Sodium Phosphate products and which ones have a better effect. I wish I knew more about how these were made and what the visual effects were after dosing them to several small reef tanks over 6 months. Like a BRS ther

It's not the TSP itself, but the impurities contained therein.

You can get food grade and othe higher purity grades.

The same is true for other chemicals. I.e. Calcium chloride for swimming pools is not something I would use in a reef, but one for cheesemaking should be fine.

edit: Oops, just noticed Randy said something similar.

Reefahholic · Jun 8, 2022

Randy Holmes-Farley said:
Trisodium phosphate is, by itself or in combination with other agents, a good cleaning agent. That does not make it any less suitable for use in a reef tank if adequately pure. It raises the pH a fair bit, which is partly why it works as a cleaner, making many chemicals more soluble at high pH.

Sodium hydroxide is used in drain openers and oven cleaners and yet is a fine alk supplement.

I do not recommend ANY ungraded additives for supplementing N and P in a reef tank. The one you show is ungraded and may not be pure. But food grade trisodium phosphate will not be much different than dosing food grade di or monosodium phosphate.

Copy that. I just posted that ungraded pic as an example of cleaner. You know I was dosing LoudWolf.

So if the Mono, DI, & Tri are all very similar, why did they make all three of those. Why not just one? Do you happened to know what each is primarily used for or go at? Maybe if I knew that I would have an easier time picking one. I do dose the other product currently, but you never know what could happen with demand which is the reason I’m trying to stock up on something, but not TSP.

Reefahholic · Jun 9, 2022

gbroadbridge said:
It's not the TSP itself, but the impurities contained therein.

You can get food grade and othe higher purity grades.

The same is true for other chemicals. I.e. Calcium chloride for swimming pools is not something I would use in a reef, but one for cheesemaking should be fine.

edit: Oops, just noticed Randy said something similar.

I was dosing food grade 99.9% pure TSP. IMO, If dosing large amounts there’s better products. I won’t dose that one again after what I observed for several months.

Reefahholic · Jun 9, 2022

I just can't decide. None of them sound like they belong in a reef. Lol

SODIUM PHOSPHATE MONOBASIC
(NaH2PO4).

HUNDREDS OF USES
INCLUDING:
Food Additive / Thickener / Emulsifier / Water Treatment / Magnesium Detection.

SODIUM PHOSPHATE DIBASIC
(Na2HPO4).

HUNDREDS OF USES
INCLUDING:
Water Softener / pH Adjustment / Anti-Caking Agent / Thickening Agent.

TRISODIUM PHOSPHATE
(Na3PO4).

CAUTION:
Concentrated solutions of Trisodium Phosphate are very caustic and can cause burns.

HUNDREDS OF USES
INCLUDING:
Cleaning Agent / Degreaser / Soldering Flux / Food Additive / Painting Preparation (De-Glosser) / Ceramic Glazes / Electroplating Solutions.

Sean Clark · Jun 9, 2022

Everything in moderation.

Sean Clark · Jun 9, 2022

There is propylene glycol in your HI-C drink. Stating that there is antifreeze in your beverage may be true but it is grossly misleading.

Reefahholic · Jun 9, 2022

Sean Clark said:
Everything in moderation.

True that. Looking at some of the uses between them all I’d have to say now that TSP would be last on my list.

Reefahholic · Jun 9, 2022

Sean Clark said:
There is propylene glycol in your HI-C drink. Stating that there is antifreeze in your beverage may be true but it is grossly misleading.

I understand there’s a lot of things that we consume or even put into our reef tanks that don’t seem to belong, but I witnessed some funky things with TSP. Enough to were I’m positive I’ll never dose it again.

Sean Clark · Jun 9, 2022

Reefahholic said:
I understand there’s a lot of things that we consume or even put into our reef tanks that don’t seem to belong, but I witnessed some funky things with TSP. Enough to were I’m positive I’ll never dose it again.

Fair enough.
Sodium hydroxide is quite capable of being dangerous and even causing burns if not handled/used properly. It also has a use case in out reef tanks in moderation.

gbroadbridge · Jun 9, 2022

Sean Clark said:
Fair enough.
Sodium hydroxide is quite capable of being dangerous and even causing burns if not handled/used properly. It also has a use case in out reef tanks in moderation.

Killing Aiptasia is the top of my list for Sodium Hydroxide

They love it.

Reefahholic · Jun 14, 2022

Randy Holmes-Farley said:
Unless one uses organophosphate chemicals (like phospholipids, DNA, etc.) there is zero difference in the form of the phosphate once it has dissolved in the water. It is all just phosphate ions.

Must be what Andre is having mixed in the lab. That stuff is gold for a starving tank. 100%

Miami Reef · Jun 15, 2022

I purchased the bottle Sodium phosphate dibasic.

@Reefahholic I checked James calculator and it said potassium phosphate only. Is that what you are using in the calculator?

Miami Reef · Jun 15, 2022

@Randy Holmes-Farley

Which are you more cautious when handling: formalin or sodium hydroxide?

Which one “scares” you more?

Randy Holmes-Farley · Jun 15, 2022

Miami Reef said:
@Randy Holmes-Farley

Which are you more cautious when handling: formalin or sodium hydroxide?

Which one “scares” you more?

Formailn because it enters the air. Sodium hydroxide is a spill concern only.

Reefahholic · Jun 17, 2022

Miami Reef said:
I purchased the bottle Sodium phosphate dibasic.

@Reefahholic I checked James calculator and it said potassium phosphate only. Is that what you are using in the calculator?

Yeah, they all have a different molar mass. But even if you don’t account for the mass it’s close enough. We dose up/down anyway according to our test results. Trisodium Phosphate was pretty close for me, but you would multiply the amount of product to use by 0.77 when you pick potassium phosphate on that calculator.

So if it called for 1.5 grams you’d mix 1.155 grams.

Same with Sodium Nitrate. Multiply by 0.84

@Randy Holmes-Farley can give you the number for the Dibasic off the top of his head. Or I can get back with you. About to head to work.