Category: water hardness

The Best Water Hardness Test Kits: How to Choose the Right One for You

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Are you looking for the best water hardness test kit? If so, you’re in luck! In this article, we will discuss some of the best options on the market and how to choose the right one for you. Water hardness is a major issue for many homeowners, and it’s important to test your water regularly to make sure that it’s within safe levels. A quality water hardness test kit can help you do just that!

Factors for choosing a water hardness test kit

There are a few different factors that you’ll want to consider when choosing a water hardness test kit. The first is the type of kit that you need. There are two main types of kits: those that test for total hardness and those that test for specific minerals. Total hardness kits are generally more expensive, but they’re also more accurate. If you’re concerned about your water hardness, we recommend going with a total hardness kit.

The next factor to consider is the range of the kit. You’ll want to make sure that the kit you choose can test for the levels of hardness that are present in your water. Some kits only test for low levels of hardness, while others can test for high levels. If you’re not sure what range you need, we recommend choosing a kit that can test for a wide range of hardness levels.

Finally, you’ll want to consider the price of the kit. Water hardness test kits can vary widely in price, so it’s important to find one that fits your budget. We’ve included a few options below that are all reasonably priced and offer a variety of features.

The best way to choose a water hardness test kit is to read reviews from other homeowners who have used the product. Once you’ve narrowed down your options, make sure to test your water regularly to ensure that it’s within safe levels. With a quality water hardness test kit, you can rest assured that your family is drinking safe water.

5 best water hardness test kit

Now that you know what to look for in a water hardness test kit, let’s take a look at some of the best options on the market:

Hach Hardness Test Kit

– The Hach Hardness Test Kit is one of the most popular options on the market. It’s a total hardness kit that can test for both low and high levels of hardness.

Hach 145300 Total Hardness Test Kit is one of the best on the market. It’s a great choice for those who are looking for an accurate and reliable way to test their water hardness. This model is easy to use and comes with everything you need to get started.

Hach 145300 Total Hardness Test Kit
Hach 145300 Total Hardness Test Kit

LaMotte Water Hardness Test Kit

– The LaMotte Water Hardness Test Kit is another popular option. It’s a total hardness kit that offers a wide range of testing options.

LaMotte 4482-LI-02 Total Hardness Test Kit is one of the best options on the market. It is a Bottle type product with a capacity of 60ml. This product is made of Polypropylene and is designed for Adult use. The LaMotte company is known for its quality products.

LaMotte 4482-LI-02
LaMotte 4482-LI-02

AquaChek Total Hardness Test Kit

– The AquaChek Total Hardness Test Kit is a great choice for those on a budget. It’s a total hardness kit that offers accurate results at an affordable price.

AquaChek SPA 6-in-1 Test Strips is one of the best options on the market for testing water hardness. These strips offer accurate results in just 15 seconds, and they are very easy to use. Simply dip the strip in the water and remove it to find out the results. The strips also come with directions for water chemistry, so you can be sure that your spa is safe and clean.

AquaChek SPA 6-in-1 Test Strips
AquaChek SPA 6-in-1 Test Strips (552244)

Industrial Test Systems WaterWorks 481108 Total Hardness Test Strip

Industrial Test Systems WaterWorks 481108 Total Hardness Test Strip is a great option for those looking to test the hardness of their water. With a three-second test time and accuracy down to 0-1000ppm, this product is perfect for anyone needing to know the levels of calcium in their water.

Industrial Test Systems WaterWorks 481108 Total Hardness Test Strip
Industrial Test Systems WaterWorks 481108 Total Hardness Test Strip

U.S. Pool Supply 7-Way Swimming Pool & Spa Water Test Kit Strips

U.S. Pool Supply 7-Way Swimming Pool & Spa Water Test Kit Strips is our top pick for the best water hardness test kit. This product is easy to use, accurate and comes in a large bottle with 50 strips. These strips test for total hardness, total chlorine, free chlorine, total bromine, pH, total alkalinity, and cyanuric acid. Simply dip a strip into the water for a few seconds, shake off the excess water, and then compare the strip’s markings to the graduated measuring scale on the side of the bottle. This product is a great value and will help you keep your pool or spa properly balanced and safe for use.

U.S. Pool Supply 7-Way Swimming Pool & Spa Water Test Kit Strips
U.S. Pool Supply 7-Way Swimming Pool & Spa Water Test Kit Strips

Some kits use chemical strips that change color to indicate the level of hardness, while others use electronic testers that give a more precise reading. Second, you’ll want to think about how often you need to test your water. If you have hard water, you may need to test it more frequently than if you have soft water.

We hope this article has helped you choose the best water hardness test kit for your needs. If you have any questions or would like to share your own experiences with testing water hardness, please leave a comment below! Thanks for reading!

Determination of permanent hardness of water

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The available methods for determination of permanent hardness of water are O’Heners method, EDTA method and Soap titration method. Initially we have to know; what is hardness? –Hardness is due to presence of bicarbonate, sulphates, chlorides and nitrates of calcium and magnesium. It is expressed in ppm (part per million) as calcium carbonate. There are two types of hardness:

  1. Temporary hardness
  2. Permanent hardness

Bicarbonate of calcium and magnesium is responsible for temporary hardness whereas sulphates, chlorides and nitrates of calcium and magnesium are responsible for permanent hardness. The salt of Na, K and NH4- do not reacts with soap; hence the presence of these salt do not creates hardness of water.

Determination of permanent hardness of water by O’hehners method
Theory: At first, the water is boiled to remove temporary hardness. When the water is boiled then, the Bicarbonate of calcium and magnesium are change into non-dissolve carbonate.
Ca(HCO3)2 → CaCO3 + H2O + CO2
Mg(HCO3)2 → MgCO3 + H2O + CO2

After that, added Na2CO3 solution. This chemical reacts with dissolved calcium and magnesium salts and converts them into insoluble carbonate.
CaCl2 + Na2CO3 → CaCO3 + 2NaCl
MgCl2 + Na2CO3 → MgCO3 + 2NaCl
The residue Na2CO3 is then determined by titrating against a standard acid. The reduction in the amount of soda added is equivalent to permanent hardness.
Burette for determination of permanent hardness of water

BrandTech 4761161 Borosilicate Glass 50mL Titrette Bottletop Burette, with Titration and Recirculation Valve

Apparatus

  • Beaker
  • Weighing Balance
  • Burette with stand
  • Pipette
  • Conical flask
  • Hot plate

Chemicals

  • N/10 Sodium carbonate solution
  • N/10 HCl acid

Indicator

  • Methyl orange

Procedure:

  1. Take 50ml of water sample into a 500ml beaker and boil for 15 min.
  2. Add 50ml of N/10 Na2CO3 solution into it with stare.
  3. Separate the precipitate with filter paper and wash the precipitate 3-4 times with a little distilled water. Take the filtrate and cool the solution to room temperature. Then, take it into a 250ml volumetric flask and dilute it up to the mark with distilled water.
  4. Take 50ml in a conical flask from volumetric flask with a pipette and titrate it against N/10 HCl using Methyl orange indicator. At the end point the color of the solution turns into reddish yellow.
  5. Take the burette reading. Let, it is v ml.
  6. For blank titration, take 50ml of N/10 Na2CO3 solution into a 250ml volumetric flask and dilute it up to the mark with distilled water. Take 50ml in a conical flask from it with a pipette and titrate it as same process against N/10 HCl using Methyl orange indicator.
  7. Determine the consumed N/10 Na2CO3 solution from the difference of this two reading.

1ml 0.1N HCl ≡ 0.005005g CaCO3

Calculation:
Volume of N/50 Na2CO3 used for removing permanent hardness in 50ml of water sample
=50 -43.5 = 6.5 ml
Normality of water due to permanent hardness:
N1V1 = N2V2
N1 × 50 = N/50 × (6.5)
N1 = 6.5 /50 × 50 = 0.0026
Amount/Lit = N × Eq.wt
= 0.0026 × 50 = 0.13 gm/lit
Mg/lit = 0.13 gm/lit × 1000mg/1gm = 130 mg/lit
As,
1mg/lit = 1ppm
Permanent hardness = 130 ppm
Result: the given sample of water contains 130ppm permanent hardness.

Determination of permanent hardness of water by EDTA method:
The temporary hardness can be removed by boiling. The permanent hardness is determined first by precipitating the bicarbonates of Ca2+ and Mg2+ by heating and filtering off.

Procedure:

  1. Take 100ml of water sample into a beaker and boil gently for 15-20 minutes.
  2. Cool the solution then filter and wash the precipitate several times. Collect both the filtrate into a 250ml volumetric flask and level upto the mark with distilled water. Then, shake well.
  3. Take 50ml of solution from volumetric flask with pipette and place into a conical flask.
  4. Add 1-5ml NH4OH/NH4Cl buffer solution. It increases the pH level and should be 10. Check the pH with standardize pH meter.
  5. Add 2-3 drops 0.1M Mg-EDTA solution and 3-4 drops Eriochrome Black T indicator. Then, shake well and the color becomes wine red.
  6. Fill up the burette with standardized 0.01M EDTA solution. Record the initial burette reading and titrate the water sample with this standard solution.
  7. At the end point the color of the solution turns into blue from wine red. Titrate carefully near the end point.
  8. Take the final burette reading. Let, it is V1 ml.
  9. Repeat the titration process at least three times.
  10. You can run a blank titration for more accurate result. Let, it is V2 ml.

Water sample Vs EDTA

Serial No Volume of water sample (ml) Burette readings (ml) Volume of EDTA solution (ml)
Initial Final
1
2
3

Permanent hardness calculation:
In case of blank titration, the calculate volume of EDTA required by sample water, V = (V1-V2)ml
The permanent hardness can be calculated by using the following formula.
1ml 0.01M EDTA ≡ 1.00mg CaCO3
∴ Vml 0.01M EDTA = V ᵡ 1.00mg CaCO3

The 100ml sample water is dilute into a 250ml volumetric flask
Hence, 50ml dilute water = 100 ᵡ 50/250 ml = 20ml sample water

Now, 20ml of sample water ≡ V ᵡ 1.00mg CaCO3
∴ 1000ml of sample water ≡ V ᵡ 1.00mg ᵡ 1000/20 CaCO3
≡ V ᵡ 1.00 ᵡ 50 ppm CaCO3

Result
Amount of permanent hardness present in the given water sample = ppm

Determination of total hardness of water

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To determine the Total Hardness of Water, EDTA is the easiest method. Reason, EDTA reacts with all metal without alkali metal and the proportion is 1:1. The main cause of water hardness is dissolved salts of calcium and magnesium. Moreover the other ions like Strontium, Iron, Barium and Manganese also contribute of water hardness. Traditional it is measured by the amount of soap that is required to produce leather. The EDTA method is more accurate and more rapid.

Mn+ + Na2H2EDTA → [M-EDTA](4-n)- + 2Na+ + 2H+

There are two types of hardness: (1) temporary hardness and (2) permanent hardness.
The temporary hardness is due to the presence of Ca(HCO3) or Mg(HCO3) or both. On the other hand, permanent hardness is due to the presence of sulphates, chlorides and nitrates of calcium and magnesium (as like CaCl2, CaSO4, MgCl2 and MgSO4) in water.

To determine the Total Hardness of Water with EDTA method initially an inorganic acid is added to convert temporary hardness into permanent hardness.
Ca(HCO3)2 + 2HCl → CaCl2 + H2O + 2CO2

At pH 10, EDTA forms colorless, water soluble stable complexes with calcium and magnesium ions. When the indicator Erichrome black T dye is added into the hard water, then the indicator forms unstable complex with calcium and magnesium ions and the solution turn into wine red. If there is no hardness the color becomes blue which is original color of indicator. Now, when this solution is titrated against EDTA, then the calcium and magnesium ions started to form a stable metal-EDTA complex. After all the free calcium and magnesium ions are consumed, the EBT is replaced by EDTA from the unstable complex and liberates the free Eriochrome Black-T. Then the water color change from wine red to blue that indicates the end point.

Apparatus:

  • Conical Flask
  • Funnel
  • Burette
  • Sand
  • Beaker
  • Pipette
  • Graduated cylinder
  • Hot plate stirrer
  • Wash bottle
  • Spatula

Chemicals:

  • Buffer solution
  • Inhibitor
  • Eriochrome black T indicator (blue color)
  • NaOH
  • Standard EDTA Solution 0.01M
  • Magnesium sulphate

Procedure:

  1. Take 50ml of water sample into a conical flask.
  2. Then add 2-3ml 1:1 HCl and boil for 2 min.
  3. Cool the solution and neutralized with the dil NaOH.
  4. Add 1-5ml NH4OH/NH4Cl buffer solution. The pH should be 10. Check the pH with standardize pH meter. (you can also add an Inhibitor, after the buffer solution)
  5. Add 2-3 drops 0.1M Mg-EDTA solution and 3-4 drops Eriochrome Black T indicator. Then, shake well and the color becomes wine red.
  6. Fill the burette with standardized 0.01M EDTA solution. Record the initial burette reading and titrate the water sample with this standard solution.
  7. At the end point the color of the solution turns into blue from wine red. Titrate carefully near the endpoint.
  8. Take the final burette reading. Let, it is V1 ml.
  9. You can run a blank titration for more accurate result. Let, it is V2 ml.

Total hardness calculation:

Serial No Volume of water sample (ml) Burette readings (ml) Volume of EDTA solution (ml)
Initial Final
1
2
3

In case of blank titration, the calculate volume of EDTA required by sample water, V = (V1-V2)ml
The total hardness (temporary + permanent) can be calculated by using the following formula.

1ml 0.01M EDTA ≡ 0.001001g CaCO3
∴ Vml 0.01M EDTA = V ᵡ 0.001001g CaCO3

Now, 50ml of water sample ≡ V ᵡ 1.001mg CaCO3
∴ 1000ml of water sample ≡ V ᵡ 1.001mg ᵡ 1000/50 CaCO3
≡ V ᵡ 1.001 ᵡ 20 ppm CaCO3

Lime soda process

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Lime soda process is one of the water softener systems. In this system calcium hydroxide and soda ash are used as reagents. By this process soluble magnesium and calcium salts are removed as calcium carbonate and magnesium hydroxide precipitated. After removal of this precipitated, we obtain soft water. Both temporary water hardness and permanent water hardness are removed by this lime softening water softener systems. Before water treatment calculate the amount of temporary and permanent water hardness, and then estimate the amount of lime and soda ash and added control with careful. In case of temporary water hardness the following reactions are take places:

Ca(HCO3)2 + Ca(OH)2 → 2CaCO3 + 2H2O

Mg(HCO3)2 + Ca(OH)2 → 2CaCO3 + MgCO3 + 2H2O

MgCO3 + Ca(OH)2 → Mg(OH)2 + CaCO3

In case of permanent water hardness the following reactions are take places:

CaSO4 + Na2CO3→ CaCO3 + Na2SO4

MgSO4 + Na2CO3→ MgCO3 + Na2SO4

MgCO3 + Ca(OH)2 → Mg(OH)2 + CaCO3

There are two type lime-soda process; cold lime soda process and hot lime soda process.

Cold lime soda process
In the cold lime soda process the reactions take place at normal temperature. The raw water is passed into a tank with a static continuous flow, at the same time a calculated amount of chemical mixture of lime and soda ash are also added a static continuous flow and then thoroughly mixed with a stirrer in this mixture tank. Afterward this water is allowed to settle. When the settlement becomes complete the water is passed by continuous up-flow process into another tank which is called filter bed. Then we get soften water.
The cold lime soda process is not suitable for all purposes. It is limited for those purposes where partially softened water needed because this process fails to precipitate completely all the hardness forming salts. The cold lime soda process is used for municipal water and cooling water softener systems. The reason in case of municipal purpose, it is not necessary to remove all water hardness forming ions. Same way cooling water should be free from temporary water hardness. In this process it is possible to remove magnesium water hardness nearly completely but calcium hardness may be remains more than 40ppm.

Hot lime soda process
In the hot lime soda process the reactions take place at higher temperature near about boiling point of water. The chemical mixing process is same as the cold lime soda process, but steam is applied in mixture tank. As a result precipitation becomes almost complete very quickly. This process is more effective than cold lime soda process. The hot lime soda process water softener systems are exclusively used for boiler purpose. In this process it is possible to remove magnesium water hardness completely and calcium hardness may be remains very low. Moreover dissolved corrosive gases also removed by this hot lime soda process.