TDS & Thermometer PEN

Total Dissolved Solids (TDS) is the total amount of mobile charged ions, including minerals, salts or metals dissolved in a given volume of water. Therefore expressed in units of mg per unit volume of water (mg/L). We also refer to it as parts per million (ppm).

One of our favourite tools to use is a TDS pen. TDS = Total Dissolved Solids. It measures all the solid particles in the water and gives you a reading of part per million. We have no idea what the solid particles from the reading of a TDS pen are. It could be minerals, metals, salts and many more. When you feed your fish, the fish eat the food and eventually poop – but at the end of the day, the food/poop get broken down into small particles by your filter. These particles stay in the water. It has nowhere to go. This will result in a higher TDS reading as it reads everything in the water including the broken-down fish waste.

So why do we use a TDS pen? We use it because we hate doing weekly water changes! Want to know when to do a water change?

Measure the TDS of the water that you use to do water changes. Some people use tap water, borehole water or remonetized RO water. If the reading of this water is for an example on average 150ppm, we normally wait till the water in the tank has a TDS of between 50-70 higher than this reading. At this stage we will do a 30% – 50% water change. This helps us not to do unnecessary water changes.

A TDS pen can also tell you if the RO water that you use are in fact RO water. A proper RO water system will get your TDS to bellow 5ppm, but even 10ppm is acceptable.

– TDS is directly related to the purity of water and the quality of water purification systems and affects everything that consumes, lives in, or uses water, whether organic or inorganic, whether for better or for worse.

– The EPA Secondary Regulations advise a maximum contamination level (MCL) of 500mg/liter (500 parts per million (ppm)) for TDS.

– Similarly  numerous water supplies exceed this level.

– For instance if the TDS levels exceed 1000mg/L it is mostly considered unfit for us as humans.

– A high level of TDS is an indicator of potential concerns and therefore warrants further investigation.

– Even our best water purification systems on the market require monitoring for TDS to ensure the filters and/or membranes are effectively removing unwanted particles and bacteria from your water.

– The TDS pen can be used in: water purifiers and filters, food (vegetable, fruits) & drink quality monitoring, pools and spas, aquariums, hydroponics.

– Hold function: Saves measurements for convenient reading and recording.

– Auto-off function: Turns off meter after 10 minutes of non-use to conserve batteries.

– Dual Range: Measures form 0-999ppm, with a resolution of 1ppm. From 1,000 to 9,990ppm, the resolution is 10ppm, indicated by drinking x 10image, Factory calibrated.

– Color : Beige

– Accuracy : +/-5%

– Weight : 68g

– Rang : 0-9990ppm

– Item size : 155mm x 28mm x 15mm

– Battery : 2 x 1.5V Button Cell battery (included) (LR44 or equivalent)

Furthermore, this is not a HM digital product, However, we also have a higher quality TDS pen available and it measures pH as well as TDS and temperature. You can check out that pen >here<.

McMerwe’s Review: We use these TDS meters daily. They are fairly accurate and we have never found one that was malfunctioning. For the price, its well worth the buy. (Review: 5/5)
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