How To Change TDS In A Shrimp Tank?

How To Change TDS In A Shrimp Tank

TDS is one of the main water parameters, stable and proper level of which can ensure you a tank full of thriving shrimps. Although it is normal that TDS will go low or high over time with water changes and other maintenance, there are multiple ways to raise or lower the TDS level of your tank water.

Here are the ways you can lower TDS in a shrimp tank:

  • Using RO (Reverse Osmosis) water
  • Using Deionized water or Rainwater
  • Regular Water changes
  • Controlled feeding, etc.

Here are the ways you can increase TDS in a shrimp tank:

  • Adding shrimp salts, minerals, fertilizers, limestones, etc.

In this article, I am going to share some authentic ways (there are some unsustainable ways too that will take your life to change TDS!)  how you can lower and increase TDS in a shrimp tank. I am giving more emphasis here on lowering TDS levels rather than increasing it, as many of you may know that high TDS is relatively more fatal than low TDS for a shrimp.

What Is TDS?

TDS refers to the sum of total dissolved solids (minerals, salts, metals) or all inorganic matters in your tank water. Any small particles or molecules that can pass through the filter are considered in the TDS number.

By testing GH and KH you will get the reading of only calcium, magnesium, carbonates, and bi-carbonates. But when you are measuring TDS, you are measuring everything in your water besides these elements. So,

TDS = GH + KH + Nitrate, Nitrite, chlorine, and other dissolved cations and anions + All dissolved Molecular Compounds

Very often you get your GH and KH, okay but only after that, you may notice that your shrimps are weak or even dead. When you do a TDS test, you can understand when your water is overloaded with solids and you have to do a water change to keep your shrimps well.

blue cherry shrimp grazing on floating plants
Owner: Natalie Skinner

What Is The Suitable TDS Level For Freshwater Shrimps?

Most freshwater shrimps thrive in the water with a TDS level of 400 ppm. Some of the freshwater shrimps who love soft water require even lower TDS water.

Different Shrimp Species And Their Required TDS

Species        Required TDS
Neo-Caridina Shrimps         150 – 250  
Tiger Shrimps         120 – 220
Crystal Bee (Caridina)         100 – 180
Sulawesi Shrimps         200 – 260

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Why Maintaining A Balanced TDS Is Important?

  • Shrimps do not like any inconsistency in the environment of their tank. A consistent level of minerals in the tank water is necessary for their life. As TDS affects the flow of water in and out of their body, changes in the number of total solids in the water will affect their life badly.
  • If the TDS level is too high or too low, it can even affect the forming of their exoskeletons as it requires a certain amount of solids in the water, not significantly more or less than that.
  • Too high or too low TDS can cause even the death of your shrimps.
cherry shrimp hiding and grazing on tube hideouts
Owner: Sarah Louise Kennedy

Why TDS Rises In A Shrimp Tank?

TDS rising is a normal process just like the ammonia or nitrate rising in your shrimp tank. Whatever you add in your tank, that will increase your TDS.

TDS increases as every day you are adding things into your shrimp tanks-shrimp foods, fertilizers, water conditioners, minerals, etc.

Sometimes it will increase even if you do not add anything. It happens when due to water evaporation the concentration of salts increases in your tank water.

How Will You Understand That Your Water Is Having A High TDS?

The high concentration of solids will affect water clarity, so when you will notice that your shrimp tank or aquarium is looking cloudy, it indicates that your water is having high TDS.

If your filter and all other water parameters are okay after checking, then you can be sure that water is being cloudy because of high TDS.

See also  What To Do With Dead Shrimp In Tank?

You will get some other signs- your shrimps will become motionless or swim sluggishly when you will do a water change. After a few days, they can even die if their molting process is badly affected.

High TDS is generally alkaline while low TDS is generally acidic. So, if your water has low pH, it also has low TDS. Similarly, if it has high pH, it has also high TDS.

new shrimp in plastic bag
Owner: Ricky Sales

What Happens If TDS Goes Too High?

Proper TDS ensures proper osmotic regulation, which is the interrelation between water and dissolved solids in the cells of shrimps’ body and the external environment of your tank.

  • Very high levels of TDS are the reason for high salinity that causes stress in your shrimps, plants, and other organisms in your tank. What actually happens is that your shrimps’ bodies are mainly comprised of water.
  • So, when the TDS of your tank water gets high, it will try to equalize with the lower TDS water of the shrimps’ body. Thus, the tank water continues passing through the shrimps’ body until the TDS levels equalize which affects your shrimps’ blood pH, digestion and weakens its immune system increasing the risk for various diseases.
  • The osmotic pressure stresses your shrimps’ osmoregulation process. They cannot adjust to the changing environment, feel suffocated, and even proceed towards death.
  • The more the difference of the solids between the water and your shrimps, the more it will cause fluid loss through their gills.
  • Excess minerals like calcium and magnesium do not harm your soft water shrimps itself (low Ph and low TDS shrimps) but can prevent hatching hardening the eggshells in the soft water shrimps. 
  • Excess minerals in the water can cause failed breeding of Caridina shrimps. The inappropriate proportion of calcium and magnesium, carbonates, and bicarbonates in High TDS water is mainly responsible for this.
  • High TDS water is slightly alkaline in nature that causes dehydration on the shrimps at a cellular level.
  • High concentrations of solids also lower water clarity and affect photosynthesis.
  • Incorporating with various toxic compounds, heavy metals it can trigger increased temperatures.
  • For the high concentration of solids in the water, the red blood cells in your shrimps’ gills will be soaked with water letting the red blood cells expand.
  • The shrimps face difficulty passing the toxins out of their body through their kidneys. This does not kill your shrimps instantly so you cannot perceive the change immediately. 

How To Lower TDS In Shrimp Tank?

Despite the fact that your water’s pH and GH are okay, you should keep an eye on your TDS whether it is optimum or not. While high TDS value is more fatal for your shrimps, low TDS values will not have those compounds that can stress your shrimps badly.

You can reduce the TDS of your water in the following ways. You may find some other ways somewhere, but they will not be feasible in the long run.

1. Using RO Water In The Tank

If you notice that the TDS levels of your shrimp tank are much higher than the optimal TDS limit for your specific shrimps, you can pull it down by diluting the water that means by adding RO or distilled water. You should add some essential minerals into RO water (as it lacks essential minerals) keeping a TDS of 0.

Shrimp King Mineral Salt is a good product to provide the minerals in RO water for your shrimp tank.

Some shrimp keepers do not like adding minerals when they want to lower the TDS number noticeably. Adding some minerals while doing a water change will ensure essential nutrients that will be needed for your shrimps’ molting process.

Reverse Osmosis (RO) units can remove up to 95%-98% of the TDS from the water with a special membrane. The remaining amount of TDS in the RO filtered water can vary with the number of TDS of your tap water.

You can remove the remaining TDS using Deionization Resin that will bond with the remaining TDS while passing through it.


  • If you do not want to add minerals, do a 5-10% water change with just RO water to keep your shrimps unaffected.
  • You have to replace the membrane depending on your use and the TDS level of your source water.
  • Never forget to drip acclimatize your new shrimps before introducing them into the tank.

2. Deionization

Deionized water has to be filtered with a reverse osmosis unit first to eliminate the non-ionic organic contaminants from the water. DI resin will change its color noticeably when it will be the time to change the resin cartridge.

red and yellow cherry shrimp on snail
Owner: Maryanne Young

3. Rainwater

If you can collect clean water while raining, then rainwatercan be a good source to fill your tank with low TDS water.

4. Change Water As Needed

TDS build-up will grow over time naturally. So, try to do a water change in your shrimp tank whenever it is needed. The frequency of water changes will depend on how fast the TDS level rises in your water.

See also  Freshwater Shrimp & Fish Compatibility Chart [Illustrated]

When you will notice that TDS is rising to the upper limits for your shrimps, get ready for a 5-10% water change. If this does not work, do another water change after two or three days later. But do not rush. Always attempt to reduce it slowly.

5. Controlled Feeding

Control feeding your shrimps. Do not overfeed them. Overfeeding will raise the build-up of waste and inorganic compounds in the tank water increasing the TDS level.

Feed them enough but make sure that there should not many leftovers. Otherwise, those leftovers will keep floating around the tank or lying at the bottom.

6. Keep Your Tank Clean

Tank cleanliness is necessary to keep the TDS lower. Along with water change clean the glass, gravels, rocks, substrate, and other areas of the aquarium. Sometimes ions cling to some substrates and rocks causing rise to your TDS.

What Happens If TDS Goes Too Low?

  • The absence or substantial lack of essential nutrients and minerals in low TDS water is not enough to give your shrimps a healthy life. They will not have proper immunity and will be more prone to diseases.
  • The lack of calcium in low TDS water will affect the molting cycle of your shrimps.
  • Biofilm microorganisms growing on every surface of a cycled aquarium provide essential nutrients (sterols, essential fatty acids, amino acids, and vitamins) to your shrimps. They are also necessary for metabolism and biosynthesis. Now, if your water is very clean it is possible that there are not enough bioavailable nutrients to fuel these processes.
  • TDS also influences the osmoregulation process of the shrimps’ gills. If your shrimps cannot be acclimated with the low TDS, water is used up in their red blood cells that can cause respiratory problems.
  • Low TDS water is slightly acidic in nature and very hydrating at a cellular level.

How To Raise TDS In Shrimp Tank?

As very low TDS water do not have adequate levels of some essential nutrients, you might want to increase it for the well-being of your shrimps when it gets too low.

Increasing TDS is relatively easier than lowering it. Because whatever you add in your water, TDS will rise. Obviously, you should add things that are necessary for your shrimps’ wellbeing. Do not fill your tank water with unnecessary stuff to raise TDS that will not be beneficial for your shrimps’ health.

  • When you will feed your shrimps and give nutrients in the water, TDS will rise.
  • Add micro nutrients-iron, zinc, Copper, Manganese, Nickel, Cobalt, Molybdenum, Selenium, Chromium, Iodine, etc. Calcium, magnesium, phosphorus, potassium, chloride, sodium, sulfur, etc.  are essential macronutrients for shrimps.
  • The necessary fertilizer that you use in your tank can be a good way to raise the TDS of your water.
  • You can use limestone to increase TDS that will also help to remove the molting issues.
  • You can put leaf litter or driftwood in the tank to increase the number of organic acids in your water.


  • Your main focus will be to increase TDS with Magnesium & Calcium at a 4:1 ratio and other minerals like Potassium as well as trace elements in a lower proportion.
  • As the dissolved solids in the tank keep increasing continuously from different sources (shrimp food, waste, water evaporation, water conditioner, plant fertilizers, etc.), you should target a slightly lower TDS value to get the optimum result.
  • So, if your shrimps’ optimal TDS is 200ppm, do target for 150ppm TDS when you change your water. If you aim for the accurate optimal TDS (in this case 200 ppm), it will raise over that within a few days.
  • If you want to use distilled water in your tank, you should raise your TDS level to an additional 80-100ppm with a mineral condition. In case you use tap water, raise your current TDS level to an additional 50ppm with the re-mineralizer.
multiple colored shrimps all grazing and having fun
Owner: Ricky Sales

How Will You Measure TDS Of Your Shrimp Tank?

With a TDS-meter, you can measure the TDS of your water. Normally, they are calibrated with a sodium chloride solution. The readings can be slightly different If you want to measure TDS of other salts.

For adaptable species of shrimps, an Inexpensive TDS Pen will do the job of checking TDS easily. For accurate results for more sensitive species like  Sulawesi shrimps, you can rely on  TDS meters. You will get both the products available in aquarium pet stores or local hardware stores at a reasonable price.

API pH and TDS test kit is another good product that will let you keep a watch on the pH and TDS levels of your water.

Dip the TDS meter into your tank water then it will show you the TDS number in parts-per-million (PPM).

See also  Do Shrimps Float When They Die?

What Does A TDS Meter Measure Actually?

TDS meter basically measures how much electrically conductive the water is. In other words, how easily current can run through the water. Actually, water is not capable of conducting electricity itself, the dissolved chemicals in your water run the electricity through it.

If your water has higher TDS that means more dissolved chemicals, the current will run easily. Similarly, if your water has lower TDS, the current will not run easily.

A TDS meter thus measures the purity of your water by sending a small electrical charge and measuring the Electrical Conductivity. The electrolytes are measured and the result is converted to the TDS number.

Limitations Of TDS Counts

The limitation of the readings of TDS meters is that you cannot see what you are measuring as it only gives you only a number without breaking down the details.

Because TDS counts everything in your shrimp tank-salts, minerals, nitrites, nitrates, ammonia, de-chlorinator, water conditioners, fertilizers, shrimp and snail wastes, etc.

So, if you add de-chlorinator or water conditioner in your tank, your TDS level will match with the required TDS, but actually, it will not ensure the perfect environment for your shrimps.

To figure out the details you have to do the GH, KH, and pH tests along with TDS. TDS value is absolutely worthless until you test other parameters.

API GH and KH test kit is a good product to monitor the GH and KH levels of your tank water.

Different Shrimps & Their Ideal Water Parameters

different shrimps' ideal water parameters infographic

Want to get a printable version of this infographic? Click here! [If you want to use this infographic on your website, please link back to this post as the source!]

Frequently Asked Questions

What is TDS shock and how to prevent it?

Like pH shock, TDS shock is another deadly accident that can cause a heavy blow in your shrimps’ life. When the TDS level suddenly falls or rises in one shot, with water changes or overfeeding, your shrimps can go into a shock.

Again, while introducing new shrimp, they find it really difficult to swim in the excessive cloudy water of your tank if you do not drip acclimate them to cope with the new environment. This can cause sickness or even death.

To prevent TDS shock always do slow and gradual water changes. And always check TDS levels while doing a water change. Try to clean any leftover of food that is floating on the water or lying on the nook and corner of your tank.

High TDS affects the molting process and weakens the shrimps gradually, but TDS shock will kill them at once. So, never take any measure to lower or raise TDS at a time.

TDS is related to water hardness that is associated with pH balance. We know, water hardness is the sum of calcium and magnesium salts in it while TDS is the sum of salts of any metal and any chemical dissolved in water.

So, TDS is also concerned with those salts that have nothing to do with water hardness or pH.

But in most cases, you will notice that low pH or soft water shrimps require low TDS water and high pH or slightly alkaline water shrimps will thrive in high TDS water.

Does water softener work to lower TDS?

Water softeners remove the carbonates of your water that is the cause of temporary hardness by introducing more chlorides in the water that causes permanent hardness.

This increased chloride level is not good for the shrimps. Water becomes softer this way, but your shrimps find the water full of dissolved minerals (chlorides, sodium), and actually, TDS is still high.

Does Peat lower TDS?

It is true that peat can lower TDS and hardness but to a little extent. The calcium and magnesium present in your water will make a bond to the peat fibers thus you can remove a bit of excess of these minerals from your water. Actually, it is not a sustainable way.

Do decaying plants, animal matters, detritus raise TDS?

TDS is concerned with the substances that can flow through the filter media. Decaying plants, animal matters, detritus such things get trapped in the filter media and increase TSS (Total suspended solids) in the water.

What is the ideal TDS range for Sulawesi shrimps?

The ideal TDS range for Sulawesi shrimps is around 200-260.

What is the ideal TDS range for Amano shrimps?

The ideal TDS range for Amano shrimps is around 150-200.

What is the ideal TDS range for Crystal Red shrimps?

The ideal TDS range for Crystal Red shrimps is around 100-200.

How often should you change shrimp tank water?

Generally, it’s recommended to perform a 10-30% water change every 1-2 weeks for a well-established shrimp tank. The frequency of water changes depends on factors such as tank size, shrimp population, and water parameters.


Therefore, to give your shrimps a stable environment, you should never lower or raise TDS in a rush rather aim for a slow change giving your shrimps the scope to get accustomed to.

Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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