Epsom salt weight?

[Ashlar]

I'm switching over from kalk dosing (not enough evap to dose the required amount of limewater) to RHF's homemade 2-part + Mg.

Question I have is that I'm a stickler for measurements, and switching over from weight to volume is irking me. So does anyone know how much 3 cups of epsom salts weigh? Or 5 cups of magnesium chloride hexahydrate?

 

[Boomer]

You can find it all here rather than me rambling on

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System
http://reefkeeping.com/issues/2006-02/rhf/index.php

 

[aquariumdebacle]

Boomer! we love it when you "ramble on!" let's face it, at least as far as we are concerned, your mere ramblings are more interesting than mosts "pontifications!"

 

[Ashlar]

Well, yes, that's what I was working from.. but from the article..

Dissolve 500 grams (about 2 ½ cups) of calcium chloride dihydrate
...
Spread baking soda (594 grams or about 2 ¼ cups)
...

But..

Dissolve Epsom salts (3 cups) and magnesium chloride hexahydrate sold by the Dead Sea Works company (5 cups) in enough purified freshwater to make 1 gallon total volume.

Just wondering if there's a weight for epsom salts and magflake.

 

[DonW]

It depends on how much moisture is in the epsom, it changes if its not perfectly dry.

Don

 

[Ashlar]

Ahh, wonder if you can drive off the moisture the same way you do baking soda.. then get a good weight.

 

[DonW]

Ahh, wonder if you can drive off the moisture the same way you do baking soda.. then get a good weight.

Its not potent enought to worry about it. It takes alot of mg suppliment to change the mg. Just put the volume on a scale and use that weight. Consumption is going to vary so dosage will need constant adjustment anyways.

Don

 

[Boomer]

Randy's weight is based on know bulk density, which gives the vol in cups. That way you do not have to weigh it, so weight is not much of a factor but you can weigh it as Don has suggested.

 

[Aquarium Scienc]

Epsom salt is not dry. It is Mg So4 7H20. That means it has 7 moles of water.

Handling Mg So4 7H20 should be done in a dry room.

Mg So4 (anhydrous) is dry.

 

[Boomer]

Epsom salt is dry. I think you are confused about that 7 mol of water. It is contained within the monoclinic crystal lattice. It is not like it is leaking out water or is wet. It can still pick up moisture form the air like any salt which, will changes its bulk density. Zeolites, like Clinoptlolite, (Na,K,Ca)2-3Al3(Al,Si)2Si13O36 · 12(H2O), also contain water in the crystal lattice but appear dry as a bone. Same for Epsom. Epsom salt is the mineral Epsomite. And to dehydrate Epsom to MgSO4 requries heating it to 116 - 224 °C.