You can buy pH tester strips from any pet shop, use them to determine the current pH. level, which is how acidic or basic the water is, and then you can buy tablets to correct the pH and alkalinity to a neutral 7.0. The brand of dip test strips I use is Jungle Quick Dips and the stabilizer I use is Jungle Correct pH, they have worked thus far since I have became an aquarium hobbyist.
I filled the tank with freshwater.
Yes but you need to buy a saltwater filter to replace the freshwater one.
The average alkalinity of a freshwater stream typically ranges from 20 to 200 mg/L as calcium carbonate (CaCO3), though it can vary significantly depending on the geology of the watershed, land use, and seasonal factors. Alkalinity is a measure of the water's capacity to neutralize acids, largely influenced by the presence of bicarbonates, carbonates, and hydroxides. Streams in areas with limestone or other carbonate-rich soils generally have higher alkalinity compared to those in silicate-dominated regions. Monitoring alkalinity is essential for assessing water quality and ecosystem health.
no because if its a freshwater tank the rain has salt in it
yes.
waterchange
Yes, most freshwater fish need a air stone in their tank. And even if they don't need one it will improve the fishes health.
Because he is from freshwater and needs to breathe freshwater instead if air.
probably not.
It is not harmful. But if you want to clean up the algae in the tank you want to get a pleco. They are very peaceful fish and will not harm angelfish. I have a pleco and three angelfish in my 35 gallon tank right now and they get along great!
10 minutes
no because if you do it will die.