All the other parameters in the tank are perfect except for the phosphate levels and carbonate hardness. The phosphate is more than 10ppm and when I test it, it looks black in the test tube. The carbonate hardness is just as bad. I am thinking about doing a water change because I can get water from a spring with 6.9 ph and add it to the aquarium. The ph is very high in the water we added to the tank before we changed, but we are going to use the spring water when we do water changes before we get the fish because its carbonate hardness and phosphate levels aren't outrageously high.
We can't get tap water to our house. The only water we can use is well water unless we want to use a 5 gallon bucket and make 15 trips to the spring and to the house.
We started out and we had the tank full of spring water once, but we used the wrong type of substrate. It made the whole tank cloudy and the filter couldn't even filter it out. So we drained it and got all the substrate out. We started again by adding fine gravel we got at our local aquarium store. We then filled it with well water. Well now we are having lots of problems with the well water too. The well water is full of heavy metals, high in phosphates, and is very hard. The ph in the well water is over 8.0.
We decided we are going to buy an RO unit. This aquarium has turned out more costly than it should have been.
What will the RO unit make the ph in the aquarium?