Thursday, August 07, 2014

HM Digital Triple Inline TDS Monitor: 3 IS better than 2


Excessive algae growth is one of the most common and most frustrating problems that that many hobbyists face.

Once algae growth gets out of hand, it can be quite a tough battle. While water changes, adding GFO and other filter media helps to lower those nutrient levels, the source of the problem is often overlooked.

Most hobbyists will assume that just because they have an RO/DI system that their water source is pure. However, regular cartridge changes and water monitoring are often neglected and that fancy 4-stage RO/DI filter now has the effectiveness of a wad of cotton in your water bucket.



Tap water quality can vary significantly from city-to-city and the amount of water used can also vary greatly from one hobbyist to the next. The general 6-8 month replacement rule doesn’t always apply.

The three measurements that are important in monitoring your RO/DI system is the input water, the water produced by the RO and the final water output through your DI cartridge.

The measurement of the input water allows to your monitor how dirty your tap water is (which can actually vary significantly throughout the day).

The second measurement of the water produced by the RO allows you to see if your TFC membrane is doing its job. The TFC membrane should remove at least 95% of the TDS from your tap water. High-end TFC membranes can remove up to 99% of TDS, such as the SpectraPure SpectraSelect Plus. For example, if your tap water measures 100ppm, water should exit the RO at 5ppm or less. An exhausted TFC membrane can ‘burn’ through your DI cartridge in a matter of hours.

The final measurement of water exiting the DI cartridge allows you to monitor the final quality of the water you are adding for top-off and water changes.


Click here to see a larger version of this diagram.

Up until now, only single-point or dual-point monitors have been available so it is often a big hassle trying to determine how your RO/DI system is performing or trying to troubleshoot what may be wrong.

The new Triple Inline TDS Monitor from HM Digital is the perfect tool for monitoring the performance of your entire RO/DI system. It allows you to easily and quickly see the TDS of the water at each of the three key points in your RO/DI system—water in, RO output and DI output—so you will know exactly when your filter cartridges need to be replaced. Quick disconnect push-in fittings are included for you to easily splice in the sensors to your RO/DI system and a simple switch allows you to easily view the readings at each point.

With the new HM Digital Triple Inline TDS Monitor installed on your RO/DI system, there should never be a reason for adding dirty water to your aquarium again!