Can I use ph down and and tap water conditioner for my plant water?

Yes but if I were you I would just use the fish tank water. Free fish manure fertilizer! and the fish get fresh water.

You can use tap water for all your house plants. They don't get special water when they are growing in the wild. If you want to help them grow buy some African Violet food and add a 1/4 tsp to a gallon of water then water your house plants with that solution about once a week. Any chlorine will evaporate out of the water after a few hours of standing.

Interesting question. I suppose if you were really into it you could phone up the person who is really already into it at the water department provider and would be able to tell you exactly what PH you are getting in you're water, with vastly high degree of accuracy and could probably send you water testing materials too.

Use the PH checker you have on the water, then you should be able to know. My tap water has chorine but that is because my dad is an fagit and doesn't wear the correct hair gel... Just like my Mom... Tramps. I worry about turning into them; but worrying itself won't change a thing.

Just use the water from the fish tank when you change it, that should add a little fertilizer into the mix as well.

tap water has a ph of 6.2 that is safe for all plants.