Water hardness variability

[gwand]

I have well water. When I bought my Anomalochromis thomasi a year ago the well water had a GH of 175 ppm, upper limits for this species. I tracked my GH over the course of a year. The GH ranged from 175 ppm to 250 ppm. Do you think this variation poses a threat to my butterfly cichlids? These fish have spawn three times over the course of the year. They seem to like the water.

 

[Back in the fold]

The range in water chemistry is probably seasonal with it being lower PPM in the spring and summer . There’s probably no way for you to know where your well originates but that aquifer starts someplace . If in the course of an entire year they’ve spawned and been healthy then don’t worry .

 

[TwoTankAmin]

I have well water. I have mesured it as low as TDS 53 ppm and as high as about 115 ppm. The pH has ranged from about 6.6 to 7.4 as well. In my case is is not so much seasonal as dependent on rainfall. The numbers rise as things go into drought conditions and they go down when there are heavy rains for and extended period.

I have not seen any ill effects in terms of my fish. The fluctuations are somewhat gradual even thought there are two clear extremes. By tis I meen they take a few weeks for the change to be fully realized.

 

[gwand]

Not only has my well water GH fallen from 250 ppm to 214 ppm but my nitrate level in the well water has fallen from 30 ppm to 5 ppm. I assume it is a dilution effect from the Fall rains. I hope the nitrate level stays relatively low for a long time.

 

[GaryE]

I have a friend on a well with hardwater. He's a fish importer. I have watched wild caught discus, newly brought in, spawn and get fry in his tanks. I've seen blackwater Bettas spawn in his holding tanks.

And so, I fall back on 'mystery thinking'. It may not always be the hardness we read on our test kits, but what the hardness is composed of that can be important. I question whether all minerals are equal in their effects.
Yes they give the same readings. but... Oddly, here I usually have the same tds as in my old house 800 km from here. I have a pH that's only slightly lower. But I don't find I have the same fish breeding easily. I can breed tetras here I couldn't at the old place, but some of my other groups give me nothing here.

In order to breed Anomalchromis thomasi, I had to reduce the 140ppm water I had back then (a few moves ago) to 50ppm, to get fry. And yet they breed in your water at a higher ppm than my old tap. Chemistry meets biology and confuses us...

 

[f_luxus]

What do you feed?

 

[gwand]

Is that a question for Gary or for Gary?

 

[TwoTankAmin]

One of may favorite sites for folks just entering the Hobby is "FINS: The Fish Information Site." While the information there is mostly accurate, it does get some things a bit wrong. However, it is great for the basics, especially for water chemistry. Here is what they say about testing GH and what the results mean:

General Hardness (GH)​

General hardness (GH) refers to the dissolved concentration ofmagnesium and calcium ions. When fish are said to prefer ``soft'' or``hard'' water, it is GH (not KH) that is being referred to.
Note: GH, KH and pH form the Bermuda's Triangle of water chemistry. Although the three properties are distinct, they all interact with each other to varying degrees, making it difficult to adjust one without impacting the other. That is one reason why beginning aquarists are advised NOT to tamper with these parameters unless absolutely necessary. As an example, ``hard'' water frequently often comes from limestone aquifers. Limestone contains calcium carbonate, which when dissolved in water increases both the GH (from calcium) and KH (from carbonate) components. Increasing the KH component also usually increases pH as well. Conceptually, the KH acts as a ``sponge'' absorbing the acid present in the water, raising the water's pH.

Water hardness follows the following guidelines. The unit dH means``degree hardness'', while ppm means ``parts per million'', which is roughly equivalent to mg/L in water. 1 unit dH equals 17.8 ppm CaCO3. Most test kits give the hardness in units of CaCO3; this means the hardness is equivalent to that much CaCO3 in water but does not mean it actually came from CaCO3.

General Hardness

0 - 4 dH, 0 - 70 ppm : very soft
4 - 8 dH, 70 - 140 ppm : soft
8 - 12 dH, 140 - 210 ppm : medium hard
12 - 18 dH, 210 - 320 ppm : fairly hard
18 - 30 dH, 320 - 530 ppm : hard
higher : liquid rock (Lake Malawi and Los Angeles, CA)

The site has two section on Water Chemistry: Beginner FAQ: Practical Water Chemistry and Altering Your Water's Chemistry

The FINS site is the more modern version of one of the older fish information sites from the early days. Some of the older member here who who have been keeping fish for longer than my 25 years may recognize it--> thekrib.com

 

[Colin_T]

General Hardness

0 - 4 dH, 0 - 70 ppm : very soft
4 - 8 dH, 70 - 140 ppm : soft
8 - 12 dH, 140 - 210 ppm : medium hard
12 - 18 dH, 210 - 320 ppm : fairly hard
18 - 30 dH, 320 - 530 ppm : hard
higher : liquid rock (Lake Malawi and Los Angeles, CA)

LOL, LA's water is liquid rock and so is South Australia's

Lake Victoria has a GH around 150-200ppm
Lake Malawi has a GH of 300ppm so it's not too bad.
Lake Tanganyika has a GH between 350-450ppm. The GH fluctuates due to rain. In the wet season the GH drops due to the rain diluting the water and minerals. In the dry season it goes up because the water evaporates and the minerals are more concentrated in the smaller volume of water.

 

[plebian]

General hardness (GH) refers to the dissolved concentration ofmagnesium and calcium ions.

This is mostly true, but GH also captures other dissolved ions such as copper, iron, zinc, manganese, etc. These are typical a minor component of public water systems but they can be substantial components of well water, e.g.

 

[TwoTankAmin]

Plebian- my last post stated the below

Most test kits give the hardness in units of CaCO3; this means the hardness is equivalent to that much CaCO3 in water but does not mean it actually came from CaCO3.
I have preferred to use TDS over my GH test kit for at least the last 15 years. It measures pretty much everything in the water but tells nothing about what exactly is in the water.

I have well water.

But I just discovered something interesting when I visited the Hach site. For those who do not know Hach,

Making Water Analysis Better​

Since our founding in 1933, Hach® has led the industry in developing innovative solutions to help our customers analyze their water more efficiently and more effectively.

Today, Hach products can be found around the globe in a wide range of lab, field, and in-process uses in municipal and industrial facilities. Hach analytics solutions are designed to give operators and managers confidence in the many decisions they make to ensure compliance, improve energy efficiency, and reduce waste in production, product quality, and utilities management.

HACH

Here is what they say about water hardness testing: Hardness (Total, Ca & Mg)

Why Measure Hardness?​

In general, hard water forms solid deposits comprised of mainly calcium and magnesium salts and can damage equipment, while soft water may be corrosive and therefore, it is important measuring and knowing levels of hardness in your process water to maintain the delicate balance between scaling and corrosivity.

While some hardness may be acceptable in certain water quality applications, others require zero hardness to prevent scaling and damage to equipment. Therefore, water softening by either precipitation or ion exchange is often necessary to remove hardness. To optimize these processes, it is sometimes important to monitor calcium and magnesium levels separately, along with total hardness.

Additionally, magnesium can interfere with other water quality tests such as nitrogen, ammonia-salicylate methods. Visit these related parameter pages to learn more about ammonia and nitrogen.

At Hach®, find the testing equipment, resources, training, and software you need to correctly monitor and manage water hardness in your specific application.


What I learned from the above is the 3rd paragraph. I knew Iron can change ammonia test results but I did not know magnesium could do so as well. This suggest that the hardness of the water in our tanks may effect the results when we test for ammonia. Most of out test kits use the salicylate methodology. However, it requires that magnesium levels be "Greater than 6000 mg/L as CaCO3" to do this. I also read it happens in water with a pH over 13.3. I know that any level of iron that can interfere with the salicylate ammonia test. Here is a list from Hach of things and their levels that do so:

The ones for us to worry about are Iron and Monochloramine. Bear in mind that the levels for nitrate and nitrite are using the Nitrogen scale. For our typical Total Ion kits the numbers would be 443 ppm for nitrate and 328 ppm. So these is not really likely to occur in a tank.