Reverse Osmosis?

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bassholedrifter

Aquarium Advice Apprentice
Joined
Sep 13, 2004
Messages
36
Location
Missouri,USA
I live in a rural area and use well water which is very hard, this greatly reduces the kind of fish I can keep and for that matter the type of fish that are readily available thru my LFS.

I would like to start a Discus tank and for them to thrive I would need to soften my water,considerably, water hardness is closely linked to pH and influences the ease in which pH can be altered. The high mineral content of my hard water acts as a buffer and counteracts the effects of pH conditioners. So what to do?

Answer, a reverse osmosis unit.

Well what I thought was going to be a simple research into what is "reverse osmosis" (RO) and what it means to the Aquarium and fish hobbiest turned into a deep and ongoing study!

O.K. what is reverse osmosis? I read what my dictionary said and almost needed a degree to understand it, so I will break it down in a very simple term, it is the act of removing chemical nutrients and minerals directly from your water source, providing you with the cleaniest puriest water available.

O.K. this is a good thing, now all I need to do is add my pH conditioners to reach my desired pH level and my fish are happy.

How does RO work?

In a RO unit, your source water is forced thru a cellular membrane (filter) which allows only very small molecular particles through, while the larger particles (salt,chemical, organic compounds, impurities, fungi, viruses, pesticides) are washed away. Removing 99% of the impurities and minerals from the water!

There are two types of membranes that can be used depending on the purpose of the water being used. For the home use of drinking water and only wanting to remove chlorine a cellulose triacetate membrane is used. However for my purpose a thin film composite is needed, to hold back the nitrates,phosphates and silicates.

There are actullay three filter stages in the ro unit, carbon filters for removing the chlorine/chloramine, the sediment filter and finaly the TFM (thin film composite).

Properly installed units require very little maintance. The carbon and sediment filters need replacing every six months while the TFM will last several years.

RO's enemies,

Water temperature for the unit to work properly should be between 33-85 degree's fahrenheit everything above or below this range will destroy the membrane. Air is an other enemy,the membrane must remane submerged at all times. If allowed to dry out it is ruined.

RO units create a lot of waste water I learned. 5 gallons of source water flow will leave you with 1 gallon of RO water!

They say there is no reason why you can't use the waste water for other purposes since on the average it is only 20% higher in minerals and salts then the original source water.

So now that you have your RO water, which is maintained in a storage container until needed for your tank, you must learn to adjust its water chemistry.With such additives as calcium,chloride,calciumsulfate,magnesium sulfate,and sodium bicarbonate. The specific ratio of chemicals would depend on what species of fish you plan to keep.

I know this is just a basic outline but I hope it helps any of you with the basic question of what is reverse osmosis....

Bass
 
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