EPSOM SALT

[okla03]

Hi, guys when I’m doing water change on my tanks I use 100L water butt. Two of my tanks are 270L and one is 60L, for 60L one I use bucket 20L all tanks get water change once a week. One is dutch style planted tank 270l with co2 dosing TS, one is like nature style 270L no co2 sometimes I dose this one too, 60l is very low light with moss, some plants shrimp and guppies. I use half tap water half RO in water butt, same in bucket. I change more the 100L in large tanks once I put water from water butt in tank I add more RO maybe all together around 120-130L.
So my question is how much Epsom salt should I add in water butt and bucket when changing water? If you need any more information please just ask.
Thank you very much for any assistance.

 

[John q]

So my question is how much Epsom salt should I add in water butt and bucket when changing water? If you need any more information please just ask.
Thank you very much for any assistance.

For a 20L water change add 1g of Epsom salt.
For a 120L water change add 6g of epsom salt.

The above additions will increase the incoming water Magnesium levels to 4.9 ppm + whatever is in your tap water.

 

[okla03]

For a 20L water change add 1g of Epsom salt.
For a 120L water change add 6g of epsom salt.

The above additions will increase the incoming water Magnesium levels to 4.9 ppm + whatever is in your tap water.

Thanks, I was adding just a pinch.

 

[dw1305]

Hi all,

Thanks, I was adding just a pinch.

"Epsom Salts" are only 10% magnesium (Mg), because of the "<"water of crystallization"> the "7H2O" in MgSO4.7H2O.

Cheers Darrel

 

[okla03]

Hi all,

"Epsom Salts" are only 10% magnesium (Mg), because of the "<"water of crystallization"> the "7H2O" in MgSO4.7H2O.

Cheers Darrel

Is that mean that I should be adding 6g and 1g as suggested by Jhon? Thanks. Excuse my ignorance.

 

[dw1305]

Hi all,

that mean that I should be adding 6g and 1g as suggested by @John q

That looks <"about right">, but you can actually <"check for yourself"> using the Rotala Butterfly nutrient calculator <"Nutrient Dosing Calculator">. I'd probably aim for 5 mg / L (ppm) Mg.

If we went with @John q quantities, you can just do some mental arithmetic, it is all just powers of 10.

I'd go you've added 0.5g to 10 litres, 10 litres is 10,000g, and you have ~ 10% Mg in MgSO4.7H2O so you've added 50 mg Mg to 10,000,000 (10 x 10^6) mg water, Take a "0" of either side and you have 5 mg Mg in 1,000,000 mg water or 5 mg / l and 5 ppm

cheers Darrel

 

[okla03]

Hi all,

That looks <"about right">, but you can actually <"check for yourself"> using the Rotala Butterfly nutrient calculator <"Nutrient Dosing Calculator">. I'd probably aim for 5 mg / L Mg.

cheers Darrel

Thanks, I’ll look into that, really appreciate all of your help. My tanks are fairly new so want to make sure I’m getting things right.