Reverse Osmosis water

Reasons for using Reverse Osmosis in a fish tank.

When using a buffering soil in an aquarium, whether it be for a shrimp tank or for a planted tank, you will often be aiming for different parameters than your tap water. Many Australian water supplies have quite high hardness which can diminish the buffering capabilities rapidly, in my experience I managed to ruin 3 bags of ADA soil in just over 3 months with Sydney tap water and weekly water changes.
One way to avoid this is to use remineralised reverse osmosis (RO) water using one of the variety of available mineral additives.

How to remineralise RO water  

There is a wide variety of additives designed for a range of needs. I use Salty Shrimp GH+ for my CRS and bluebolts. For my cherry shrimp I use a mixture of tap water and Salty Shrimp KH/GH+. 

Whenever I get a new batch of minerals I always mix to the desired hardness. I then take a TDS reading and use this as a baseline when making more.

What is Reverse Osmosis?

Reverse osmosis is the process where water is pushed through a semi-permeable membrane. The membrane allows water through whilst not allowing the majority of salts, bacteria and organics. In a reverse osmosis filter there are several stages with a simple portable unit using 2 stages whilst installed units could have 7 or more. The first stage of most filters is a charcoal filter, often referred to the odour and taste reducer, which is very effective at removing sediment organic compounds and chlorine. The RO membrane will then remove most of the remaining salts and minerals leaving almost pure water. An optional stage is to then have de-ionising resin (DI) which will remove all the remaining impurities and reduce the total dissolved solids (TDS) of the water to 0.

RO Unit review - Filter systems Australia portable 3 stage

I use a portable 3 stage RO/DI unit from Filter Systems Australia and re-mineralise the water with Salty Shrimp gH+ to around 150 TDS to achieve the desired hardness and perform water changes for my caridina shrimp. I also use pure RO water in my automatic top up as this replaces the water lost to evaporation without increasing the TDS of the tank over time.

The portable unit I have has been a great investment as I rent in a small apartment so there isn't anywhere to have a mounted system. The unit retails for $190 which is a bit of an initial investment but in the long run it will be much cheaper than buying water from a pet shop and you also have full control and know the maintenance schedule of the unit. 

I have been using this product for the last 5 years and have produced thousands of litres of water and spent less than $500 for the unit and replacement parts. The service I have received from FSA every time I have had any questions or needed any replacement parts has been first class. The carbon filter should be replaced every 6 months for $18 and the RO membrane should be changed approximately every 4 years and is the biggest investment at $85 for a replacement. De-ionising resin costing $25 will need replacing depending on the incoming water supply lasting 6-10 months.

RO production in the kitchen.

Benefits of making your own RO water.

• Using remineralised water will increase the life of your soil as it wont be having to buffer tap water to the desired parameters.
• Is cheaper than purchasing water from a pet shop if you require a large volume and you know the unit has been well maintained to ensure the best water quality.  
• You can ensure the best parameters for your shrimp as there are a wide variety of mineral additives.