Epsom salt for hot tub
- Thread starter Jeff piper
- Start date
- May 23, 2015
- 24,447
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Adding Epsom salt (magnesium sulfate) adds sulfates to the water. Sulfates are bad for metallic components, especially heaters, because they enhance certain forms of corrosion.
As well, that lead content looks unusually HIGH (10ppm) and that level certainly exceeds US safety standards. Skin absorption of lead is minimal but any water ingested at that concentration would be harmful. At the usage rate you describe (7kg/1200L), you would be looking at 58ppb (0.058ppm) lead. US drinking water standards has a max permissible level of no more than 15ug/L (15ppb).
Where did you get that stuff?? Is that from an agricultural supplier? I would definitely NOT use it.
As well, that lead content looks unusually HIGH (10ppm) and that level certainly exceeds US safety standards. Skin absorption of lead is minimal but any water ingested at that concentration would be harmful. At the usage rate you describe (7kg/1200L), you would be looking at 58ppb (0.058ppm) lead. US drinking water standards has a max permissible level of no more than 15ug/L (15ppb).
Where did you get that stuff?? Is that from an agricultural supplier? I would definitely NOT use it.
DangerBoy
Well-known member
Epsom salt is just hydrated Magnesium Sulphate. The iron and lead in that product are just impurities likely caused by the salts coming from a low-grade source. Not surprsing considering that product comes out of China which has a reputation for producing and exporting lots of products with dangerous levels of heavy metals in them.
Doing the math, 7 Kg/1200L in your spa equates to a concentration of the salt at 0.064 Kg/L. Multiply that by the concentration of lead in the salt you get 0.064 Kg/L x 10 mg/Kg = 0.64 mg/L of Lead and double that for Iron.
1.28 mg/L concentration of Iron is undesirable and may cause you considerable problems with iron staining not to mention a bad smell and foul taste. The Canadian (and probably EPA) guideline for Iron in drinking water is 0.3 mg/L and that guideline is an aesthetic guideline rather than a health guideline. Your tub water would have at least 4 times that level of iron (yuck) in it if you added that salt at the rate of 7Kg/1,200L.
I couldn't find any Canadian or EPA recreational water guideline criteria for Lead but I could find some criteria for Freshwater Aquatic Life (FAL) for Total lead which includes the dissolved lead and the lead found in any suspended solids (e.g. adsorbed to suspended clay or silt particles). Those guideline criteria varied depending on the Total Hardness of the water but for the range of TH of 100 - 150 mg/L as CaCO3, the Lead criteria for FAL is in the range of 3 - 5 micrograms/L. Converting the units that is 0.003 - 0.005 mg/L. That means the concentration of Lead you'd have in your tub would be 128 - 213 times what the criteria limits are for protecting freshwater aquatic life ( e.g. ducks and waterfowl) and all or nearly all of that Lead would be dissolved which would make it much easier to be absorbed through the skin.
Based on this analysis, I recommend you don't use that product both for the high Lead and Iron concentrations. Both would be very undesirable; the lead for possible health reasons and the iron for aesthetic reasons.
I believe we (Canada) produce Epsom salts in the province of Saskatchewan. That product may be more pure and not have the high iron and lead content. If you really want to try Epsom salts in your tub, I suggest you try to find a product with less impurities.
Doing the math, 7 Kg/1200L in your spa equates to a concentration of the salt at 0.064 Kg/L. Multiply that by the concentration of lead in the salt you get 0.064 Kg/L x 10 mg/Kg = 0.64 mg/L of Lead and double that for Iron.
1.28 mg/L concentration of Iron is undesirable and may cause you considerable problems with iron staining not to mention a bad smell and foul taste. The Canadian (and probably EPA) guideline for Iron in drinking water is 0.3 mg/L and that guideline is an aesthetic guideline rather than a health guideline. Your tub water would have at least 4 times that level of iron (yuck) in it if you added that salt at the rate of 7Kg/1,200L.
I couldn't find any Canadian or EPA recreational water guideline criteria for Lead but I could find some criteria for Freshwater Aquatic Life (FAL) for Total lead which includes the dissolved lead and the lead found in any suspended solids (e.g. adsorbed to suspended clay or silt particles). Those guideline criteria varied depending on the Total Hardness of the water but for the range of TH of 100 - 150 mg/L as CaCO3, the Lead criteria for FAL is in the range of 3 - 5 micrograms/L. Converting the units that is 0.003 - 0.005 mg/L. That means the concentration of Lead you'd have in your tub would be 128 - 213 times what the criteria limits are for protecting freshwater aquatic life ( e.g. ducks and waterfowl) and all or nearly all of that Lead would be dissolved which would make it much easier to be absorbed through the skin.
Based on this analysis, I recommend you don't use that product both for the high Lead and Iron concentrations. Both would be very undesirable; the lead for possible health reasons and the iron for aesthetic reasons.
I believe we (Canada) produce Epsom salts in the province of Saskatchewan. That product may be more pure and not have the high iron and lead content. If you really want to try Epsom salts in your tub, I suggest you try to find a product with less impurities.
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It is agricultural magnesium and to me it seems to have a high lèad content and once you dilute it into 1200L of h20 I don't know if that helps . I was suprised that it had any lead at all. Im not sure if that is common with all agri product or just this particular sample . I think pharmaceutical grade should negate the lead problem. It was recommended to use 5-7 kg per 1200L
Thanks for the expertise. I will return the product.
Thanks for the expertise. I will return the product.
It is agricultural magnesium and to me it seems to have a high lèad content and once you dilute it into 1200L of h20 I don't know if that helps . I was suprised that it had any lead at all. Im not sure if that is common with all agri product or just this particular sample . I think pharmaceutical grade should negate the lead problem. It was recommended to use 5-7 kg per 1200L
Thanks for the expertise. I will return the product.
My daughter plays competitive soccer. She takes epsom salt baths when she is particularly sore from a rough match. Get good stuff from the pharmacy or sports med supplier, and use it in your bath tub. For the reasons stated by people much smarter than I, I would not use in my hot tub. I just wanted to chime in that people do soak in this stuff. It just needs to be good quality (certainly not from china) and used in a tub. My daughter claims that it helps muscle soreness and stiffness quite a bit.
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