Float Tank Epsom Salt Calculator

Enter your tank volume and target specific gravity to get the exact kilograms of Epsom salt to dissolve. Includes saturation check, 25 kg bag count, and magnesium concentration. Nothing uploaded.

Exact kg of salt 25 kg bag count Saturation check ? SG presets

Tank Settings

Presets:

Results

SG 1.00 (pure water)SG 1.35
SG 1.280
Epsom salt needed
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25 kg bags
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Concentration ?
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Magnesium ?
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Dissolving tip: Add the salt to hot water (50°C+) first, stirring until fully dissolved, then top up to the target volume. Epsom salt dissolves faster in hot water. Run the pump for 30 min after mixing to ensure full dissolution.

Learn more about float tanks and Epsom salt

How much Epsom salt do I need for a float tank?

A standard 800-litre float tank at SG 1.28 requires approximately 360 kg of Epsom salt (magnesium sulphate heptahydrate) - around 14-15 bags of 25 kg. The exact amount depends on target specific gravity and tank volume. Use the calculator to get the precise amount for any combination.

What specific gravity should a float tank be?

Commercial float tanks typically target a specific gravity of 1.28 to 1.30. This provides reliable floatation for the vast majority of body types. The Dead Sea is approximately SG 1.24 at the surface, which is sufficient to float but lower than the standard float pod setting. Higher SG provides more buoyancy and a more pronounced floating sensation.

Can you add too much Epsom salt to a float tank?

Yes - Epsom salt has a maximum solubility of approximately 710 g/L at 25°C (increasing slightly with temperature). Beyond this concentration, the salt will not dissolve and will settle out of solution. For a standard float tank, the target SG of 1.28 is well within solubility limits. The calculator includes a saturation check that warns if your target exceeds the solubility limit at your water temperature.

FAQ

How much Epsom salt do I need for a float tank?

A standard 800-litre float tank at SG 1.28 requires approximately 360 kg of Epsom salt (magnesium sulphate heptahydrate) - around 14-15 bags of 25 kg. The exact amount depends on target specific gravity and tank volume. Use the calculator to get the precise amount for any combination.

What specific gravity should a float tank be?

Commercial float tanks typically target a specific gravity of 1.28 to 1.30. This provides reliable floatation for the vast majority of body types. The Dead Sea is approximately SG 1.24 at the surface, which is sufficient to float but lower than the standard float pod setting. Higher SG provides more buoyancy and a more pronounced floating sensation.

Can you add too much Epsom salt to a float tank?

Yes - Epsom salt has a maximum solubility of approximately 710 g/L at 25°C (increasing slightly with temperature). Beyond this concentration, the salt will not dissolve and will settle out of solution. For a standard float tank, the target SG of 1.28 is well within solubility limits. The calculator includes a saturation check that warns if your target exceeds the solubility limit at your water temperature.

Last reviewed: June 4, 2026