# My first batch of RO water



## The Abbott (18 Sep 2010)

Hi all, I'm currently making my first batch of ro water, my question is what readings should I get when I test it before adding salts etc, should it all be zero????? . I'm using the API liquid test kits for gh/kh etc etc 

Cheers
Rich


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## Ed Seeley (19 Sep 2010)

Get a TDS meter to check your RO unit is working right.  Easy and accurate.


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## Another Will (19 Sep 2010)

Yep, I used to use a TDS (total dissolved solids) meter with my RO unit. Test your tap water and it should be in the hundreds. After going through the RO unit, it should be reading virtually 0. It's also a good way to see when your membrane is on the way out, as the tds value will go up.

A uk independent sells them here, although you can pick them up cheaper elsewhere.

Remember to re-mineralise your water, or cut it with tap water, so that you get correct KH,GH. 

One problem I had with RO water was that I got massive BGA infestation in the tank, after the first couple of weeks. The normal measures sorted this out, and ensuring adequate nitrates held it at bay.

Hope this helps.


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## jm_ (9 Nov 2010)

i would  re-mineralise your water as i dont like tap (yuck!) but seems many get on just fine with 33% - 25% cuts per change

The TDS pen is what you need and if you have DI pos look for zero - 

Marines under 10 and aim for ZERO always
If Tropicals -- under 100% and lesser the cut of tap to 10% -- might sill want to  re-mineralise your water a bit thou

Balance out what's good for you, if you have RO without DI your never get TDS zero

Sorry bit old post, but some good info there for anyone reading


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