RO water

[flyfisher110]

I am brand new to aquarium's. When I bought a 20 gal tank I asked them if it was OK to use bottled water (reverse osmosis) they said it was. Now I find it is not OK. Can this be fixed or do I have to drain the water and add different water or do something special like clean everything off rinse out the tank etc. The rock and fake plants and everything are in the tank now. (No fish yet)
The only other water I have is softened water and purified water (carbon filter and particle filter) and outside town water. (not accessible in winter.

 

[ZxC]

Softened water is fine, just add some gH booster, 4 degrees is plenty.

RO is also fine, gH and kH boost.

 

[J.Mcpeak]

Home water softeners using sodium replacement are not ideal I don’t think.
Ion exchange units for human consumption aren’t much better.

Either of these will leave you with unbalanced water and in both cases you need to add some powder so;
If you’re going to do it.....RO and maybe DI with replacement minerals is ok.
This will give you a clean slate of 0 TDS water which is then reconstituted with gh/KH minerals etc. to suit your requirement.

 

[King Fisher]

Water softener removes calcium and magnesium. It doesn't touch TDS, will remain the same.