hoppycalif

Dolomite is used as a source of magnesium in the substrate - the calcium is just icing on that cake. You don't necessarily need it, because you can get magnesium other ways, in the water. Your hard water may or may not have lots of magnesium. Your water quality report doesn't say how much of either calcium or magnesium the water has, but the combination seem to range from 10-15 dGH.

CricketMclean

Yeah it's tough to get really useful information. Especially from me lol. This is what I know about my water.
Kh 161
Calcium was 80 to 100 (couldn't really tell for sure after the 4th drop)
Phosphates .25
These were the tests included in my hand kit. I don't have one for General hardness

I download this from the city. Is any of that helpful?

Oh I also have this.
Mg. 25.67
Ca. 72.17
Na. 107.40
K. 4.34

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hoppycalif

I would conclude from that information that you probably don't need to be concerrned about extra magnesium. Your tap water should have plenty.

CricketMclean

Good news thank you!

azappetti

Is it possible to make a granular mineralized soil substrate (3 to 5 mm), such as commercial, that does not dissolve in water?
regards

BoneyTee

I am trying to do this process for my 75 gallon planted aquarium. I am having trouble tracking down the Dolomite. It seems like most substrates are either crushed coral or aragonite now. Does anyone know if aragonite would work instead or if i have some other option to supplement the dolomite?

hoppycalif

Amazon has dolomite: https://www.amazon.com/Dolomite-Lime...=dolomite+lime and I suspect Ebay also does.

BoneyTee

I saw that but I thought I read somewhere that Dolomitic Lime and Dolomite that used to be commonly used as a saltwater substrate are not the same thing and the lime is corosive. I did find aquarium substrate dolomite on ebay, but she shipping was twice the price of the gravel since it would come from over seas.

hoppycalif

Dolomite is a rock that contains both magnesium carbonate and calcium carbonate. As rocks it can have a widely varying percentage of magnesium carbonate. When it is ground up and sold for agricultural use it is sometimes called dolomitic lime - which means it contains a significant proportion of magnesium and not just a trace of it. Lime is not a specific material, but a mix of calcium compounds, but we also use that term for calcium oxide, which is corrosive. Dolomitic lime is just about any calcium and magnesium containing rock that you want to call it. (All of this is just my opinion, based on a lot of reading over several years. You know, rocks are very rarely anything close to a pure chemical compound, and dolomite is commonly what one group of rocks is called.)

BoneyTee

Hmm ok, the reason I was sticking away from the agricultural dolomite was because I thought it wasn't safe in an aquatic setting. I live in a region with very hard water, so I may not need it anyhow. The aquifers here are silurian dolomite.