Ziuck

For freshwater common

I do have a Kenmore watter softener with yellow bag Morton salt.

Tap
PH 7.8 - 8.4 depends on day!
GH 3*
KH 15*
Ammonia 0
Nitrate 0
Nitrites 0
PPM 405

RO
PH 6.4
GH 0
KH 0
Nitrate 0
Nitrites 0
Ammonia 0
PPM 5

I have all the supplements for RO so I can buffer and raise PH without issue. Should I mix the two (tap and RO?)

Luniyn

What kind of fish are you looking to house? And are you looking to do fresh or salt water tanks (only ask because doesn't the salt remain in the water?) The tap water looks fine to me except for the change in pH. Adding any RO to that would only cause more problems so don't mix them. How big is the tank you will be using? If it's large enough then doing a small water change with even drastically different pH of water, won't effect the overall system all that much. In a smaller tank, you will need to treat the water you are adding and make sure it is stable before adding it.

Now having said all that, if you don't mind the expense of the RO water and all the buffers and other chemicals you will need to buy, then that will always allow you to dial in the conditions exactly like you want them. So if money isn't an issue then go for the RO.

Mike

Regarding your tap water - is the ppm amount a measure of the total dissolved solids (TDS)? If so, that seems very high, like borderline an EPA issue.* *Is this well water?* My tap tds is around 120 and out of the RO it is between 5 and 7 ppm tds.*

For water changes and top-offs I use primarily RO mixed with a small percentage of carbon filtered (PUR filter to remove chlorine/chloramine) tap water.

Ziuck

I am not certain where I got 405 at first. The tests I have been coming up with are 250-260ppm. This is straight TAP from the city.