Question about reverse osmosis filters

Jareardy

AC Members
Dec 29, 2008
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San Dimas, CA
My grandparents (who I live with) have a reverse osmosis filter and I was going to use this for my fishtank thinking that it would soften the water and allow me to have fish that normally don't do well in hard water. Well I went to test the product water with one of those strip test kits you get from the lfs and the water hardness showed the same as what was coming out of the hose.

Should this happen? Or should there be a marked difference between the two sources?
 
jpappy is right about the strips often being inaccurate. If it's still reading as hard with a liquid test kit then the membranes need to be replaced. Where I live, RO membranes tend to need replacing twice as frequently as recommended due to the high mineral content of our tap water.
 
You need the RO units with 5 filters.THe ones with just one probably won`t do much.THe TDS (need meter)should be close to zero and I think the GH also should be close to zero.
 
Mine drops the TDS from about 350 on the input side to 25 on the output. The pH goes from 7.8 to 7.0 in the process. Even a value of 25 ppm of TDS is still a GH of about 1.5 so it's not a zero but it is much softer. The inlet water I have measured using a KH/GH kit at well over 12 on both parameters.
 
Just figured out that it's probably everything needs to be replaced. It's been over ayear and we ahve extrememly hard water so the membrane and filters are probably used up.
 
well maybe... shouldn't be that bad... anyway... try using a soft water machine if you want better results, my tds meter shows 20 ppm from the machine output, the original untreated water is about 300 ppm, after my RO, the water is about 2-3 ppm :D seems I don't need a DI

a water softener machine should cost about 300$ and works WONDERS
 
A residential water softener will leave the TDS at as high a number as it started. The difference will be that the calcium and magnesium are replaced by sodium. That provides little benefit in what we consider softness / hardness in the aquarium arena. A properly working RO will actually remove a large fraction of the total dissolved solids.
 
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