Hydration plan
Water follows salt. This plan uses a simple citrate electrolyte mix to get fluid into your body and keep it there, with a daily water target and serve schedule built around your weight and your day. Citrate salts carry less sodium per gram than table salt, so each serve holds more salt material for the same sodium and the dose is easier to measure. Any salt that isn't absorbed stays in the bowel, where it may help keep stool soft.
Learn the science
Talk to your GP first if you have kidney disease or a history of kidney problems, heart failure, high blood pressure managed with a low-salt diet, liver disease, or Addison's disease. Also check if you take ACE inhibitors, ARBs, potassium-sparing diuretics or other medicines that affect potassium, or if a doctor has limited your fluids.
Pregnant or breastfeeding, or under 18? Get advice before using this plan. For vomiting or diarrhoea, use a medical oral rehydration solution instead.
Keep your total daily sodium in view, including food. The WHO suggests under 2,000 mg a day, and the Australian upper limit is 2,300 mg. Check labels on any other electrolyte drinks you use.
Sodium is the main salt in the fluid around your cells. Where sodium goes, water follows. That one rule explains why the right salts hydrate you better than plain water alone.
Sodium arrives in the gut
Dissolved in your drink, sodium reaches the small intestine, where most absorption happens.
Sodium pulls water across
Transport proteins carry sodium through the gut wall, some paired with glucose. Water follows by osmosis.
Water reaches your tissues
Fluid enters the bloodstream, expands blood volume and hydrates organs more efficiently than water alone.
Some stays in the bowel
Sodium that isn't absorbed keeps water in the lower gut, which helps keep stool soft. Magnesium and citrate ions can do the same, which is why magnesium citrate is sold as a laxative, but at doses many times higher than the 10 mg of magnesium in a serve.
Where this mix sits. One serve in 450 mL is about 20 mmol/L of sodium. That is in the range of common sports drinks, and well below a medical oral rehydration solution (about 75 mmol/L). It is a daily hydration drink, not a treatment for vomiting or diarrhoea.
Limited evidence The first three steps are well established physiology. The extra stool-softening effect from small amounts of unabsorbed sodium is plausible, but hasn't been tested at these doses.
The mix uses citrate forms of sodium, potassium and magnesium for most of its minerals, with a smaller share of iodised table salt for taste and iodine. Here is what that changes.
| Compared with | Citrate salts | Chloride salts |
|---|---|---|
| What your body turns it into | Citrate is converted to bicarbonate, an alkaline buffer. | Chloride stays as chloride and adds to the body's acid load. |
| Effect on urine | Raises urinary citrate and pH. Citrate binds calcium and helps stop kidney stone crystals forming. Well established | High salt intake increases calcium lost in urine, which raises stone risk. |
| Stomach comfort | Potassium citrate is typically gentler than potassium chloride. Limited evidence | Potassium chloride can irritate the stomach and taste harsh. |
| Taste | Mild and slightly tart. | Sharp, salty. |
| Sodium by weight | About 23% (as the dihydrate). One serve needs about 606 mg of sodium citrate for 140.7 mg of sodium. | About 39%. The same sodium needs about 358 mg of table salt. |
| Dissolved particles per sodium ion | About 1.3. Three sodium ions and one citrate ion make four particles. | 2. One sodium ion and one chloride ion. |
| In this mix | About two thirds of the sodium, plus all of the potassium and magnesium. | About one third of the sodium, kept for crisp flavour and iodine. |
More salt by weight, not more particles. Citrate carries less sodium per gram, so a serve holds more powder than the same sodium from table salt. That makes a small dose easier to measure, and it is a practical point, not a health benefit. Our judgement
It does not mean more dissolved particles. Per sodium ion, citrate gives fewer. And once sodium is absorbed, your body spreads it through its own fluid balance, whichever salt it came with. No study shows citrate salts reach organs or tissues more evenly. Our calculation
"Easier on the kidneys" has limits. For people with healthy kidneys, citrate is the kinder form, and potassium citrate is a standard medicine for preventing kidney stones. But the kidneys still have to clear every milligram of sodium and potassium. Citrate does not make a high-salt day harmless, and it is not safe for people with kidney disease to take extra potassium.
Each benefit is tagged so you know what is solid and what is a bonus.
Faster, fuller hydration
Sodium drives fluid absorption in the small intestine, so more of what you drink reaches your blood.
Well establishedReplaces what sweat takes
Sodium is the main mineral lost in sweat. Extra serves on hard training days replace it.
Well establishedPotassium balance
Supports fluid balance, nerve signals and muscle function, and offsets some of sodium's effect on blood pressure.
Well establishedNo sugar
Many commercial electrolyte drinks are high in sugar. This one has none, so it suits all-day sipping.
Well establishedKidney-stone friendly profile
Citrate raises urinary citrate, which works against calcium stone formation. The dose here is far below a prescription.
Limited evidence at this doseSofter, more regular stool
Fluid held in the bowel by unabsorbed sodium and a little magnesium may support regularity alongside fibre and water.
Limited evidenceSteadier energy and focus
Even mild dehydration can dull concentration and mood. Staying topped up helps you avoid that dip.
Well establishedIodine from iodised salt
The salt in the mix adds a small, steady iodine supply, which the thyroid needs.
Well establishedMagnesium kept for night
Only a small amount is in daytime serves. The larger dose is taken in the evening, so it won't push gut motility by day.
Protocol design choice
Each serve is designed to deliver 210 mg sodium, 90 mg potassium and 10 mg magnesium. A scant ¼ measuring teaspoon weighs about 1.13 g.
| In one serve | Amount | What it does |
|---|---|---|
| Sodium (from sodium citrate) | 140.7 mg 67% of sodium target | Draws fluid into the bloodstream and, where unabsorbed, into the colon to soften stool. |
| Sodium (from iodised salt) | 69.2 mg 33% of sodium target | Adds crisp mineral flavour. Also brings 106.8 mg of chloride. |
| Potassium | 89.9 mg | Fluid balance, nerve signalling and muscle function, offsetting sodium's effect on blood pressure. |
| Magnesium | 9.9 mg | Kept low by day on purpose. The larger magnesium dose is taken separately at night. |
| Target per serve | 210 mg sodium · 90 mg potassium · 10 mg magnesium | |
Make a batch
Enter how many serves you want to mix. Weights scale to match. Untick magnesium on the right if you leave it out.
| Ingredient | Per 100 serves | Your batch |
|---|---|---|
| Total |
- Weigh each powder on a kitchen scale that reads to 0.1 g.
- Add all powders to a dry jar and shake hard for 60 seconds so the heavier salt crystals blend evenly with the lighter citrates.
- Shake the jar for 5 seconds before every use to stop it settling.
How the numbers are worked out
Daily water and serve targets
Water target. 35 mL for every kg of body weight. For example, an 80 kg person aims for 2.8 L a day.
Electrolyte serves. 2 to 3 serves on non-exercise days, each in 400 to 500 mL of water. On heavy exercise days, 3 to 5 serves, with the 5th only when sodium from your food is low. Space serves evenly through the day.
Our judgement The plan suggests 5 serves only when three things apply together: a heavy exercise day, hot or humid weather and low-sodium food. Otherwise it suggests 4 on a heavy day and 3 on a non-exercise day. You can still pick any serve count that your day allows, and body weight sets the water target but not the number of serves.
Plain water. At least 40% of your daily water should be plain water without salts. We use 450 mL per serve and drop to 400 mL if that is needed to protect the 40%.
Our addition Heavy exercise days add 750 mL to the water target, and hot or humid weather adds 500 mL. These top-ups are general guidance, not part of the base protocol. Without them, five serves would take up most of your day's water. Adjust to how much you actually sweat, and drink to thirst as well.
This is general information, not medical advice. Individual needs vary.
How the citrate claims were checked
Fluid and sodium. Sodium drawing water across the gut wall is well established. Trials of oral rehydration solutions also found sodium citrate worked as well as sodium bicarbonate.
Stool softening. Poorly absorbed ions hold water in the bowel, and that is how saline laxatives such as magnesium citrate work. Those products use doses far above one serve, so the effect from this mix is a small, plausible nudge, not a proven one.
Particles. Worked out from molecular weights: citrate gives about 1.3 dissolved particles per sodium ion, chloride gives 2. The idea that citrate spreads sodium more evenly to organs has no supporting evidence, so this page doesn't claim it.
Sources and further reading
WHO, Salt reduction fact sheet
NHMRC, Sodium: nutrient reference values for Australia and New Zealand
NIDDK, Eating, diet and nutrition for kidney stones
Islam et al., Gut: sodium citrate compared with sodium bicarbonate in oral rehydration
Elliott et al., Gut: sodium, glucose and water absorption in oral rehydration solutions
Health Canada product monograph: magnesium citrate as an osmotic laxative
Pair your hydration with an eating plan.