Just curious how these would differ if dosing in a reef tank?
Differences between Sodium Phosphate Dibasic, Monobasic, and Trisodium Phosphate?
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Chrisv.
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If I remember correctly there are differences in how readily each form dissolves-- but it's been a while.
Probably most relevant is that they have different molecular weights, so if you need to account for the added sodium atom when dosing. monobasic = NaH2PO4, dibasic swaps out a hydrogen for a sodium, Na2HPO4. 138 grams of monobasic in 1 L of water for a 1M solution, 142 g of dibasic in 1L for a 1 M solution, etc.
All things being equal, trisodium adds three times more sodium to your water than monobasic (dibasic adds 2x more sodium than monobasic). Given how much you would actually dose and assuming that you do water changes, the added sodium is probably irrelevant.
So-- the differences are probably ...academic.
Probably most relevant is that they have different molecular weights, so if you need to account for the added sodium atom when dosing. monobasic = NaH2PO4, dibasic swaps out a hydrogen for a sodium, Na2HPO4. 138 grams of monobasic in 1 L of water for a 1M solution, 142 g of dibasic in 1L for a 1 M solution, etc.
All things being equal, trisodium adds three times more sodium to your water than monobasic (dibasic adds 2x more sodium than monobasic). Given how much you would actually dose and assuming that you do water changes, the added sodium is probably irrelevant.
So-- the differences are probably ...academic.
gbru316
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I didn't even realize you could dose TSP in a tank. I thought it was just for cleaning, TIL!
I just bought a bottle to clean my new (to me) stand before painting it and setting up the tank. Since I plan on running ULNS for SPS, that bottle might see double duty down the road.
I just bought a bottle to clean my new (to me) stand before painting it and setting up the tank. Since I plan on running ULNS for SPS, that bottle might see double duty down the road.
Chrisv.
2500 Club Member
haha I am pretty sure you're not even really supposed to use it for cleaning anymore. It was great in various detergents, but the added phosphate in the waterways got the environment grumpy. They still sell it, but it's not common in dishwasher detergent and laundry soap anymore.
gbroadbridge
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Just try to get food grade. Something from the cleaning shelf may contain some impurities.
Randy Holmes-Farley
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Small differences in potency and the effect on alk and pH, but the emphasis is on small.
OP
OP
After dosing a ton of Trisodium Phosphate on this tank I’d rather dose a different phosphate product which I am currently, but also curious as to which ones are less (cleaner type) products. The TSP never gave me any kind of green algae on the glass or rocks. The corals didn’t seem to benefit even with very high amounts which is not what I experienced the first time using it, but I also never used this much.
So is there just a plain sodium Phosphate product or just the DI and Mono? I think I would rather try Mono because the Tri didn’t do that good for me.
Which one is less cleaner type phosphate?
OP
OP
I didn’t realize TSP was used for cleaning until recently. For me it was a poor product that didn’t seem to benefit the corals much at all.
I never saw any green on the rocks or glass. Just dark brown “cleaner type” results. Lol.
I wonder if the other DI and Mono are essentially the same? I’m just trying to figure out which one is better from a availability standpoint, but also cheap and easy to obtain here in the US.
It’s sucks that we don’t know what some of these products are on the market since they don’t list it. The only one I know for sure is Seachem Flourish Phosphorus. It’s “Potassium Phosphate.” I wonder why they picked potassium phosphate over Mono, DI, or TRI. ??
If anybody knows please fill me in.
OP
OP
I still don’t know what Andre put in his product, but all I can say is Wow. It’s so easy for the corals to uptake it that it’s not even funny. He had raw chemicals mixed professionally in a Lab. Stuff is crystal clear. Within 24 hrs I appreciated a marked difference in the tank. Within a few weeks the corals had gained a lot of color and some were almost completely colored up.
This really gets me curious about all the different PO4 products and why some aren’t really working that well and others are working extremely well.
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The form of the chemical is no indication of purity. Look to other indications, such as food grade, USP grade, ACS grade etc.
The possible forms are:
Na3PO4 (trisodium or maybe just sodium phosphate)
Na2HPO4 (disodium phosphate)
NaH2PO4 (monosodium phosphate)
H3PO4 (phosphoric acid)
They can have substantial moisture in the crystals (hydrates), but that just impacts potency, not purity.
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Randy Holmes-Farley
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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.
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It was developed as a freshwater product where potassium is in short supply and is a needed nutrient.
It is no benefit in a reef tank is potassium is already OK (or high).
OP
OP
Yeah for sure. I’ve never been a fan of anything with other elements in it. Especially with the amount I’m dosing I’m sure it would drive up the potassium level eventually.
OP
OP
What would you pick as the best choice not including TSP. I’m done with that one. Is there just a regular food grade sodium phosphate? Even on Amazon they list Mono, DI, Tri, etc.
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All sodium phosphate (and potassium too) is mono, di or tri, or a mix of them.
Loudwolf sodium phosphate dibasic is a fine choice from Amazon.
OP
OP
Yeah that is what it looked to me. Ok, so I will buy some Sodium phosphate dibasic to keep on hand. I’m assuming I can still plug this into the James calculator to make the solution? Is the molar mass close enough to TSP and the others.?
Randy Holmes-Farley
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Yes. None of the calculations are perfect, but with rock and sand binding likely, it is some trial and error anyway.
OP
OP
Agreed. Even if it’s off by .01 ppm we just dose up or down according to the test results. I do have a buddy that calculates everything for me to molar mass in Excel, but honestly unless somebody is trying to be super precise it’s not really that important. Most of us probably have our total water volumes either over or under estimated anyway.
Appreciate you Randy!
OP
OP
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 investigates.
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 investigates.
