Drinking Water?


New member
Will it be ok to use drinking water from the grocery store for top off water? I ran out of top off water this morning and don't feel like goin' to my fish store this evening. So, I was wondering if it would be ok to use drinking water this evening and tomorrow morning? I'll be goin' to get RO water from my fish store tomorrow afternoon.



New member
I would avoid the use of drinking water unless it has been processed by ro/di because some of these waters are just nothing more than a tap water from the town indicated on the bottle.


New member
Just get a few gallons of distilled water and you should be fine, can't get much more pure then distilled, I've been using it for top-off for the past week, if you have a TDS meter just make sure it's zero though, some companys may use coper and there might be some in the water


My first choice would be the RO processed drinking water, second distilled because of the copper concern.


Reef Monkey
Premium Member
It's certainly going to depend on the drinking water. If it's been either distilled (probably not) or purified using reverse osmosis AND it doesn't have anything added to it for "flavor", you'll probably be fine. There are plenty of people who have kept successful aquariums using nothing but tap water for top-off, so getting a TDS reading of 0 probably isn't all that necessary. Before I got my own RO/DI unit, I was known to use tap water just run through some carbon for top-off. It was never more than a day or two in a row, but I never saw any ill effects or signficant changes in water chemistry afterwards.