Depending on your systems evaporation. Will not work if too high.
Securely place a large water bottle upright in your sump lid slightly below your waterline. Filled with your ro
water. After it is secured(whether by clamps, cut and bent acrylic etc... Unscrew the top.
Will act as emergency top off for a few days.
Not good for long term but could get you by if can't buy and setup an auto top off before you leave.
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