Holy cow mate that water looks terrible. When Toledo treats it water during the summer to try to counter the microcystin toxin that comes from blue green algae in the western basin I run all my tap water through a pre-filter full of activated charcoal, plus I have a large filter bag full of charcoal in the 2nd stage of my sump.
RO is great as long as the chlorine levels are are not elevated. The first stage membrane removes chlorine. If levels are elevated, as they are in Toledo during the summer, up to 6 times higher than normal, the the membrane which should last 9-12 months become exhausted much faster. Once exhausted this kinda derails the RO process in stage 1. The membranes on the $800 units we used to use at work I think were about $150 to replace. The pricing would be determined by the type & size of the RO unit you chose.
I have nearly lost my trophs to bad city water 3 or 4 times. The charcoal pre-filter in combo with routine de-chlorinating has been my only successful strategy during the summer here.