Originally Posted by RascalGoneWild
Water tested results are in!!
Alright those are the results.
I think this is the source of your green water. Nitrates at 40 is high, and a pH of 8.4 is high (and for a betta, cory, pleco and loach). Coupled with the light that was on for 12 hours a day, and no live plants, this is certain to allow algae to thrive.
Is the pH of the bottled water you use also 8.4? Or is there something in this tank (calcium-base gravel, rocks) raising it this high? It may turn out that your tap water at 7.8 would be far better, as a pH of 8.4 is likely (though not always) to be combined with hardness as well. Also wondering if there are nitrates in the bottled water, you might want to test it.
Nitrates should be reduced to 10ppm as this would eliminate some of the "food" for the algae causing the green water. Others have mentioned this earlier. Live plants help, and regular (at least once a week) partial water changes of 1/3 the tank volume.
The nitrite reading is also a problem. In an established tank, ammonia and nitrite should remain "0". I suspect this is due to changing the filter media so much; as someone poiinted out, this creates mini-cycles every time. In a larger aquarium with more bacteria on surfaces in the aquarium than in the filter this would not be an issue, but not in a 10g with no plants.