Adding Phosphates Dropped Nitrates

[DraggingTail]

I started adding seachem flourish and it dropped my nitrates.

I did this to deal with red slime algae.

I got a small diatom bloom at first but not too much now.

I have been adding 6ml per day to 80 gallon.

Why did my nitrates drop?

 

[Ocelaris]

Sometimes phosphates can be the limiting nutrient and helps complete the cycle.

 

[Auto-pilot]

If you don't have any Phosphate in your water your algae and your bacteria will not grow because they need phosphate to grow. As soon as you add phosphate they are going to start growing and bloom using your nitrate because it is needed to grow algae and or bacteria. You need Phosphate and nitrates as nutrients to grow organic material as long as they are there it will grow, they also need an energy source. For algae light is an energy source for bacteria people commonly dose vodka, vinegar, Nopox, and other things as a carbon source. By dosing organic carbon you will jump start the bacteria by giving it "Food" and cause it to grow in your tank. As a result the bacteria growing uses your nitrate and phosphate if its available.