Cheap way to raise GH?

[mrV]

I'm aware that baking soda can be used to raise the KH of RO water, does anyone know of a cheap way to raise the GH? Additives cost a fortune

Buy gypsym (model gypsym, what is almost pure CaSO4) from hobby shop. Be sure, it's gypsum. Go to the nearest pharmacy and ask them about MgSO4 or MgCl2. They both increase GH. But because you use RO-water, you should use some mineral salt too: ro-water lacks trace elements.

Conductivity meter is excellent purhace when playing with water chemistry. Because when you add any stuff to water, it affects on conductivity.

 

[njparton]

I'm aware that baking soda can be used to raise the KH of RO water, does anyone know of a cheap way to raise the GH? Additives cost a fortune

Buy gypsym (model gypsym, what is almost pure CaSO4) from hobby shop. Be sure, it's gypsum. Go to the nearest pharmacy and ask them about MgSO4 or MgCl2. They both increase GH. But because you use RO-water, you should use some mineral salt too: ro-water lacks trace elements.

Conductivity meter is excellent purhace when playing with water chemistry. Because when you add any stuff to water, it affects on conductivity.

Thanks