Nitrates and Phosphates??

[RustyBuckets]

I've read a few posts where some have claimed that their phosphate levels drop if they add nitrates. What is the mechanism behind this?

I understand the nitrogen cycle where bacteria turn ammonia into nitrites and then nitrates, but just dont understand the inverse relationship with nitrates and phosphate.

Thanks!!

 

[Gtinnel]

When algea or corals consume nitrates they have to consume phosphates with it. So if either of those are 0 then the other doesn't get used. Once the one that was zero is added they both start being used again.

 

[RustyBuckets]

Ok, that makes sense. Thank you!!

 

[Clownfishy]

Is the consumption equal parts ?

 

[Gtinnel]

There is a ratio and I think the ratio is different from specific coral and algea to another but I'm not positive about that. I do know it's not a 1:1 ratio, some things I've read say that it stays fairly close to the Redfield ratio.

 

[BroccoliFarmer]

Nitrates get taken up faster than phosphates. I had to learn this one too. My nitrates would be at zero but my phosphates would continue going up. Once i started dosing nitrates..boom...phosphates dropped. Then i had other problems when BOTH my levels bottomed out and then bring on the dinos

 

[Gtinnel]

It's supposedly fairly close to 16:1 Nitrate to phosphate, but again that's just what I've read.

 

[ScottB]

Similar to what @Gtinnel posted about coral consumption, I believe there is also a bacterial consumption issue. When one nutrient is limited, the bacteria tend to starve out, allowing the present nutrient to accumulate.

Once the limited nutrient is restored (dosed) the bacterial colony starts feeding again (on the PO4 in your example) and replicating, and feeding, and replicating.

That bacteria -- that is now "gut-loaded" with PO4 is SPS food. They don't feed directly on PO4 itself, but indirectly via the bacteria. Lou Ekus explains this well on youtube.

 

[MomSaysNo]

I've read a few posts where some have claimed that their phosphate levels drop if they add nitrates. What is the mechanism behind this?

I understand the nitrogen cycle where bacteria turn ammonia into nitrites and then nitrates, but just dont understand the inverse relationship with nitrates and phosphate.

Thanks!!

THANK YOU for asking this question! I was just having the same concerns with my tank. Low nitrates and high phosphates.

 

[ScottB]

THANK YOU for asking this question! I was just having the same concerns with my tank. Low nitrates and high phosphates.

@RustyBuckets
I will speculate, but the takeaway is really just my repeated experience that PO4 will fall (every time) when you dose NO3 into an NO3 depleted system.

The bacterial colony that process PO4 require the presence of NO3 to replicate. In our aquariums there are countless examples of growth being limited by the absence of a given element. A very common example is chaeto won't grow even with high PO4 and NO3 because Fe (iron) is missing.