I would not use tap in a reef ...Just my opinion.
All that is needed besides water is in the salt mix.
you were lucky to have only algae problems as many heavy metals are also often present.
For me [ still struggling ] knowing the source water is not part of my problem is a big help.
I know what I am trying to remove in my system..PO4
I have a float valve in a 32g brute that holds my ro
water and a 32g brute I mix the water and salt in.
Every time I make new salt water my ro
barrel fills back up so it is ready when I need it again. I usually let salt mix at least 24 hours ,so even if wanted to go again it ready right then to be mixed.
I have seen fish go sideways and almost die after 6 months in a house with copper pipes..The level grew slowly till almost toxic [FO
system] using municipal tap.