gypsum in water

On May 6, 1:45 pm, Vreejack wrote:
> At my new place the water seems to contain a lot of gypsum. I'm still
> trying to guess how that is going to affect my new tank in the long
> run. I think it might be harmless as the local nursery sells the
> stuff as an inert additive to garden soil, but it leaves an
> unattractive grey-white deposit on the bottom of a test bottle I just
> evaporated. In the water heater it separates into sulfur and calcium
> but I do not think that is going to happen in the aquarium.

After testing my water I found it cannot be gypsum. My GH and KH are
both 7, so the permanent soluble salts must be very low. I think I
should have realized that from the fact that this grey powder is not
all that soluble. I know there is some gypsum because the hot water
faucet releases H2S when I open it, but the amount must be small.
This residue must be magnesium carbonate, or "chalk." I'm going to
have to look up what this means for my tank.