Buoy and Ultima Replenisher take almost opposite approaches to electrolyte hydration.

Buoy Hydration Drops are unflavored liquid drops designed to be added to water, coffee, tea, smoothies and other drinks. Buoy says its Hydration Drops contain no sugar, sweeteners or flavors and are intended for flexible use throughout the day. (Buoy)

Ultima Replenisher is a flavored electrolyte powder and stick-pack product. The brand positions its products around zero-sugar daily hydration and offers a large selection of fruit-flavored formulas. (Ultima Replenisher)

So which is better?

It depends on what you want from an electrolyte product.

Buoy makes more sense when you want unflavored drops that can disappear into almost any beverage. Ultima makes more sense when you want a flavored, zero-sugar electrolyte drink with clearly disclosed amounts of potassium, magnesium and other minerals.

Buoy vs Ultima Replenisher at a Glance

Feature	Buoy Hydration Drops	Ultima Replenisher
Format	Liquid drops	Powder / stick packs
Flavor	Unflavored	Fruity flavors
Sugar	0 g	0 g
Added sweeteners	None claimed by Buoy	Stevia
Sodium	About 50 mg per Buoy serving squeeze	About 55 mg per serving
Potassium	Included, but Buoy’s comparison page doesn’t give an equivalent headline amount	250 mg
Magnesium	Included	100 mg
Calcium	Included	47 mg
Chloride	Included	78 mg
Other nutrients	Buoy markets 87+ trace minerals	Phosphorus, vitamin C and trace nutrients
Beverage flexibility	Excellent	Primarily water
Main strength	Unflavored, flexible format	Flavor + disclosed mineral profile
Listed example price	~$0.33/serving	~$1.05/serving
Best for	Flexible everyday use	Flavored zero-sugar hydration

Buoy’s own comparison page lists approximately 50 mg sodium per serving and a $39/120-serving example, while Ultima’s comparison gives approximately 55 mg sodium per serving and a $20.99/20-stick example. (Buoy)

One important limitation: the two brands don’t present their nutrition information in exactly the same format, so not every mineral can be compared on an identical basis.

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What Is the Difference Between Buoy and Ultima?

The easiest way to understand the products is to forget the branding for a moment.

Buoy is an electrolyte additive

You add a small amount to whatever you’re already drinking.

Buoy recommends one quick squeeze as a serving and says the drops can be used in water, coffee, tea, smoothies, juice and other beverages. Its current product page describes one serving as approximately 1.5 mL. (Buoy)

That makes Buoy unusual among electrolyte products.

You don’t necessarily need to make a separate electrolyte drink.

Ultima is an electrolyte beverage mix

Ultima uses scoops or stick packs that are mixed into water. The current Ultima site describes its products as zero-sugar daily electrolyte mixes and offers numerous flavors and varieties. (Ultima Replenisher)

That makes Ultima much closer to the traditional electrolyte-powder experience:

open packet → pour into water → mix → drink.

And that difference matters more than it might appear.

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Buoy vs Ultima: Electrolytes

This is where the comparison becomes more interesting.

Buoy’s Hydration Drops currently advertise sodium and a broader collection of minerals, with the company describing the product as an ocean-sourced electrolyte and trace-mineral formula. Buoy says its product contains 87+ trace minerals. (Buoy)

Ultima takes a more conventional label approach. Its current product information identifies several individual electrolyte quantities, including approximately:

55 mg sodium

250 mg potassium

100 mg magnesium

47 mg calcium

70 mg phosphorus

78 mg chloride per serving. (Buoy)

That gives Ultima an important advantage for shoppers who want to know exactly how much of several individual minerals they’re getting.

Electrolyte comparison

Electrolyte	Buoy	Ultima Replenisher
Sodium	~50 mg	55 mg
Potassium	Included	250 mg
Magnesium	Included	100 mg
Calcium	Included	47 mg
Chloride	Included	78 mg

The important caveat is that Buoy’s public comparison does not disclose every mineral in the same standardized numeric format, so I would not manufacture equivalent figures simply to make the table symmetrical.

That is one place where the two products are difficult to compare directly.

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Which Has More Sodium?

The answer is surprisingly close.

Buoy’s comparison page lists approximately:

50 mg sodium per serving

while its Ultima comparison lists:

55 mg sodium per serving. (Buoy)

So it would be misleading to describe Ultima as a dramatically higher-sodium product.

The more notable difference is what comes alongside the sodium.

Ultima clearly discloses substantial amounts of:

potassium

magnesium

calcium

and chloride. (Buoy)

Winner for disclosed potassium and magnesium

Ultima Replenisher

Winner for sodium

Essentially a tie at the stated serving sizes.

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Buoy vs Ultima for Heavy Sweating

This is where you should be careful.

Both products contain electrolytes, but their standard servings are relatively modest in sodium compared with high-sodium electrolyte formulas.

Buoy lists roughly 50 mg sodium per serving, while Ultima lists about 55 mg. (Buoy)

That means neither should automatically be described as the ideal choice for someone losing large amounts of sodium during prolonged, sweaty activity.

For heavy exercise, the right electrolyte product depends on:

exercise duration

heat

sweat rate

individual sweat sodium concentration

and the rest of the person’s diet.

For ordinary activity

Either can fit.

For prolonged heavy sweating

Compare the sodium amount against your actual needs rather than assuming that any electrolyte drink is sufficient.

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Buoy vs Ultima for Everyday Hydration

This is where Buoy has its clearest practical advantage.

Buoy is designed to be added to other drinks throughout the day. The company specifically suggests water, coffee, tea, smoothies and other beverages. (Buoy)

That means you can keep drinking whatever you already enjoy.

Ultima works differently.

The product is designed around flavored electrolyte beverages, with numerous flavors available from the current lineup. (Ultima Replenisher)

Choose Buoy for:

unflavored flexibility

Choose Ultima for:

a flavored electrolyte drink

This isn’t really a nutrition question.

It’s a daily-use preference.

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Taste: Buoy vs Ultima

Buoy

Buoy Hydration Drops are designed to be unflavored. The manufacturer says the product contains:

no sugar

no sweeteners

no flavors. (Buoy)

That is useful for someone who doesn’t want every glass of water to taste like fruit punch.

The downside is equally obvious:

If you like a sweet, flavored drink, unflavored drops may feel underwhelming.

Ultima

Ultima uses stevia and natural flavor systems in its flavored formulations. Its current product line includes flavors such as lemonade, berry, grape, raspberry, orange, watermelon and several variety packs. (Ultima Replenisher)

Taste winner

Buoy: better if you want little or no change to the taste of your drink.

Ultima: better if you want a flavored hydration drink.

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Sweetener Comparison

This is one of the clearest differences between these products.

Buoy

The manufacturer says its Hydration Drops contain no sugar, sweeteners or flavors. (Buoy)

Ultima

Ultima’s standard flavored products are sugar-free but use stevia for sweetness. (Ultima Replenisher)

So the choice is straightforward:

No sweetener → Buoy

Sweetened but sugar-free → Ultima

Neither choice is automatically better for everyone.

Some people dislike stevia. Others prefer a flavored drink and find unflavored mineral drops less appealing.

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Calories and Sugar

Both products are designed to avoid the sugar found in conventional sports drinks.

Ultima currently promotes its electrolyte mixes as:

zero sugar

zero calories

zero carbs. (Ultima Replenisher)

Buoy likewise markets its Hydration Drops as containing no sugar and no sweeteners. (Buoy)

Winner

Tie

This isn’t where the meaningful difference between the products lies.

The decision comes down more to:

format

taste

electrolyte profile

sweetener preference

and how you use the product.

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Ingredients: Buoy vs Ultima

Buoy

Buoy describes its Hydration Drops as an ocean-sourced electrolyte and trace-mineral formula and says it contains 87+ trace minerals. (Buoy)

The company’s current marketing also emphasizes its liquid format and says the product dissolves into beverages without the need for a flavored powder. (Buoy)

Ultima

Ultima’s formulation emphasizes:

sodium

potassium

magnesium

calcium

chloride

plus other nutrients and vitamin C in its standard products. (Buoy)

Which ingredient profile is better?

There isn’t enough evidence here to make a universal claim.

The differences are primarily:

Buoy → liquid mineral drops + trace-mineral positioning

Ultima → clearly quantified electrolyte blend + flavored powder.

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What About “Bioavailability”?

Buoy strongly markets the liquid format as highly bioavailable and says its dissolved ionic minerals can enter the bloodstream quickly. (Buoy)

That’s an important manufacturer claim, but it shouldn’t automatically be interpreted as proof that Buoy provides superior real-world hydration compared with Ultima.

The same principle applies to claims about:

“cellular hydration”

“instant access”

or other absorption advantages.

Without a direct, independently assessed comparison between the finished Buoy and Ultima products, the safer conclusion is:

Buoy uses a liquid delivery format, while Ultima uses a dissolved powder after mixing.

That’s a factual distinction.

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Price: Buoy vs Ultima

Price is another interesting difference.

The Buoy comparison page gives an example of:

$39 for 120 servings

or approximately:

$0.33 per serving. (Buoy)

The same comparison lists an Ultima example at:

$20.99 for 20 stick packs

or approximately:

$1.05 per serving. (Buoy)

But there is a catch.

Buoy recommends using its drops multiple times throughout the day—its current product page says 4–7 drinks per day. (Buoy)

That means comparing only:

$0.33 vs $1.05

doesn’t tell the entire story.

Example daily cost

Buoy’s comparison article estimates roughly:

$1.32–$2.31 per day

depending on whether four or seven servings are used. (Buoy)

Ultima’s cited example is:

about $1.05 per day

for one serving.

So:

Cheaper per serving → Buoy

doesn’t necessarily mean:

Cheaper per day → Buoy.

That’s an important distinction.

Prices also change with subscriptions, retailers, promotions and package sizes.

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Buoy vs Ultima for Travel

Both formats work well for travel, but differently.

Buoy

The liquid format can be added directly to whatever beverage you’re already carrying or buying. (Buoy)

Advantage

No flavor and no separate flavored drink.

Ultima

Stick packs are pre-portioned and easy to carry.

Advantage

One packet = one prepared drink.

Travel winner

Buoy for flexibility.

Ultima for simple single-serving preparation.

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Buoy vs Ultima for Work

Imagine you’re sitting at a desk all day.

You already drink:

coffee in the morning

water during work

tea in the afternoon.

Buoy fits naturally into that routine because its drops are designed for multiple beverages. (Buoy)

Ultima is better if you actually want a separate flavored hydration drink during the day.

Winner

Buoy for invisible integration.

Ultima for a dedicated flavored drink.

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Buoy vs Ultima for Fasting

Both products are marketed as sugar-free, and Ultima’s current site describes its products as zero calories and zero carbohydrates. (Ultima Replenisher)

Buoy’s Hydration Drops likewise contain no sugar or sweeteners. (Buoy)

That makes both potentially compatible with fasting approaches that permit non-caloric beverages.

However, “fasting” can mean different things.

A strict fast may have rules that differ from a fasting routine that permits non-caloric electrolyte products.

Winner

Tie, assuming the specific formulation fits the person’s fasting rules.

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Buoy vs Ultima for Keto

Both standard products are sugar-free.

That makes both relevant for people who want to avoid added sugar.

The difference is:

Buoy

No sweeteners

Ultima

Stevia-sweetened

So:

Strict no-sweetener preference → Buoy

Low-carb + flavored drink preference → Ultima

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What About Workout Hydration?

This is where neither product should be oversold.

Ultima provides more clearly disclosed potassium and magnesium per serving, but its sodium content is only about 55 mg. (Buoy)

Buoy’s example serving is approximately 50 mg sodium. (Buoy)

For someone doing a long endurance event in hot conditions, those are not particularly high sodium servings compared with dedicated high-sodium electrolyte products.

For short or moderate activity

Either may fit depending on personal preference.

For prolonged, heavy sweating

Look at sodium needs first, not just the number of minerals listed on the label.

And remember that neither standard product provides substantial carbohydrate for endurance fueling.

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Buoy vs Ultima: Who Should Choose Which?

Choose Buoy if you want:

• Unflavored electrolyte drops
• No sweeteners
• No sugar
• Flexible use in water, coffee, tea or smoothies
• A liquid format
• Small servings throughout the day
• Something that doesn’t taste like a sports drink

Choose Ultima if you want:

• A flavored electrolyte drink
• Zero sugar
• Stevia rather than sugar
• Clearly disclosed potassium and magnesium amounts
• Powder or stick-pack convenience
• A wide selection of flavors
• A standalone drink rather than an additive

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Winner by Category

Category	Winner	Why
Unflavored	Buoy	No flavors or sweeteners
Flavored	Ultima	Broad flavor selection
Sodium	Tie / very close	~50 vs 55 mg per cited serving
Potassium	Ultima	250 mg disclosed
Magnesium	Ultima	100 mg disclosed
Sugar	Tie	Both sugar-free
No sweeteners	Buoy	No sweeteners claimed
Zero calories	Tie	Both marketed as zero-calorie
Beverage flexibility	Buoy	Designed for many beverages
Single-serving convenience	Ultima	Stick packs
Price per serving	Buoy	Lower at the cited prices
Flavors	Ultima	Much broader selection
Heavy-sweat hydration	Neither automatic winner	Both standard servings are relatively low in sodium
Everyday flexible use	Buoy	Designed around multiple daily beverages
Overall	Depends	Different products for different habits

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Buoy vs Ultima Replenisher: Final Verdict

Buoy and Ultima Replenisher are both sugar-free electrolyte products, but they’re built for different hydration habits.

Buoy is an unflavored liquid electrolyte drop designed to be added to beverages throughout the day. The company says one serving is a quick squeeze of about 1.5 mL and recommends adding the drops to multiple drinks. (Buoy)

Ultima is a flavored electrolyte powder designed to be mixed with water. Its current product lineup emphasizes zero sugar and offers a large variety of flavored formulas. (Ultima Replenisher)

The most clearly disclosed mineral difference is on the Ultima side: approximately 55 mg sodium, 250 mg potassium, 100 mg magnesium, 47 mg calcium, 70 mg phosphorus and 78 mg chloride per serving. (Buoy)

Choose Buoy when:

You don’t want flavor or sweetness.

You want to add electrolytes to coffee, tea, smoothies or water.

You prefer a liquid-drop format.

You value flexibility more than a traditional electrolyte-drink experience.

Choose Ultima when:

You want a flavored hydration drink.

You want a clearly quantified potassium and magnesium contribution.

You prefer powder or stick packs.

You want zero sugar without giving up sweetness.

The simplest answer

Want unflavored, flexible electrolyte drops? Buoy.

Want a flavored, zero-sugar electrolyte drink? Ultima.

Want more clearly disclosed potassium and magnesium? Ultima.

Want no sweeteners and the ability to add electrolytes to almost any drink? Buoy.

Doing prolonged, heavy-sweat exercise? Compare sodium needs rather than assuming either product is automatically sufficient.