Algae is most likely happening because of the water. :-( Most people try to use ro
water as it doesnt have the nutrients like nitrates and phosphtes that tap water has.
Can you get water from your lfs
maybe? Mine charges 50 cents a gallon and I even used the water machines you find at supermarkets for water, they generally charge 30 cents a gallon.
Another cheaper in thelong run option is to get your own unit to make water. I have this unit:
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It's portable so you can hook it up to your sink or to a garden hose like I do. Just an option. Otherwise youre doing what you have to as far as lighting and feeding.
You might want to test your tap water for nitrates and phosphates just to see what you are putting into the tank.