I Need Help Understanding Water Softness and Fish/Plants

[FLFishChik]

Ok, so I don't have a water hardness testing kit, but according to my City's website our water is soft "about 100 mg/L (or expressed in different units, about 6 grains per gallon)" - per their website.

So, please help me here. I don't really understand what this means. Do I need to add anything to my water (I have Cardinal Tetra, Panda Corydoras, Betta, Nerite Snails and Ghost Shrimp along with low-tech/low-light plants). I just started dosing easy green for the plants, but is there other things I need for the water?

[modified lung]

That's a perfect hardness for most things. I wouldn't mess with it.

[nabokovfan87]

On 7/16/2022 at 5:04 PM, FLFishChik said:

Ok, so I don't have a water hardness testing kit, but according to my City's website our water is soft "about 100 mg/L (or expressed in different units, about 6 grains per gallon)" - per their website.

So, please help me here. I don't really understand what this means. Do I need to add anything to my water

Does this help?
https://www.aquariumcoop.com/blogs/aquarium/ph-gh-kh

[FLFishChik]

On 7/17/2022 at 4:30 AM, nabokovfan87 said:

Does this help?
https://www.aquariumcoop.com/blogs/aquarium/ph-gh-kh

Yes, kinda 😂. I’ll have to go really study it and then perhaps buy a testing kit! Thank you!

Edited July 17, 2022 by FLFishChik

[Biotope Biologist]

The USGS rates 100 mg/l of calcium carbonate as moderately hard. Soft would be below 60 mg/l. Either way I agree with @modified lung that is a perfect place to sit. Calcium carbonate is an acid buffer in your water. So it helps to keep stable pH especially when weak acids are present like CO2. Which your plants and fish friends respire.

[Mmiller2001]

It can get confusing when the word Hardness is used. There's soft and hard water (GH). And then there's Karbonate Hardness (KH). KH is the buffering capacity of the tank and made up of carbonates, bicarbonates and phosphates. This can affect the alkalinity of your water. As KH rises, alkalinity shifts water more alkaline (above 7.0pH). And vise versa. 

GH is simply a measure of calcium and magnesium in the water. It can be one or the other or a combination of both. But GH represents true soft or hard water. 

At a 5.5dGH, your 100mg/L is a perfectly acceptable range for your plants and livestock. The information you really want to know, if interested, is the ratio of calcium to magnesium. This matters a lot. Ideally you want a 4:1, 3:1 or 2:1 calcium to magnesium ratio. See if that water report lists Ca and Mg.