top off water question

Is the purified water you can fill into jugs from the store ok to use for my salt water tank or is it the same as tap water realy? Or does anyone know where to gettop off water for cheap mixed or non mixed with salt

Reef Keeper Supply in Arlington has free R/O water, on a donation basis. Make sure people donate enough to keep the R/O unit going with new membranes. Otherwise the water from a store like Top Foods etc. Is barely filtered more than tap water.

Just buy an RO unit.

Where can i buy one and how muchare they

Home depot, lowes, Dr fosters and smith, marine depot, I even have one for sale.
Most will cost you around $100 for a small one but I have a coralife 4 stage for $60.

Pm sent