Nitrate And Phosphate Levels

[montyII]

In the pinned EI article it says that Nitrate and Phosphate should be around

Nitrate 20-30 ppm
Phosphate 1-3 ppm

for plant growth.

My nitrate is usually around 10, phosphate 5-10.

Is that nitrate level too low for plant growth and is that phosphate level dangerous for the fish?

I dose a light version of EI as it's a low light/no CO2 tank. I tested 3 days before water change day.

Thanks.

 

[Themuleous]

If it were me I would up the NO3 to around 20-30ppm, probably near 30ppm. And not worry about the PO4. Only at really high levels say over 10ppm does PO4 become a problem.

Plants need P and N in a set ratio, at the moment they have lots of P available to them but cant use it all as they cant get enough N. Increasing the N level will result in the plants being able to increasing their P usage. This might also bring the P level down a bit.

Sam

 

[mibson]

If it were me I would up the NO3 to around 20-30ppm, probably near 30ppm. And not worry about the PO4. Only at really high levels say over 10ppm does PO4 become a problem.

Plants need P and N in a set ratio, at the moment they have lots of P available to them but cant use it all as they cant get enough N. Increasing the N level will result in the plants being able to increasing their P usage. This might also bring the P level down a bit.

Sam

I thought Levels of No3 above 15 were not good for fish?

 

[Themuleous]

I have read that, but as far as I'm concerned its a myth. Tom Barr kept discus at over 100ppm NO3 with no problems. I know from my own experience that running at 40-50ppm NO3 never seemed to harm my fish, and I've had some over 4 years now.

Sam

 

[montyII]

If it were me I would up the NO3 to around 20-30ppm, probably near 30ppm. And not worry about the PO4. Only at really high levels say over 10ppm does PO4 become a problem.

Plants need P and N in a set ratio, at the moment they have lots of P available to them but cant use it all as they cant get enough N. Increasing the N level will result in the plants being able to increasing their P usage. This might also bring the P level down a bit.

Sam

OK, will add more NO3. That makes sense that the PO4 isn't being taken up without enough NO3.

I wonder if that explains why I still get a bit of algae and some of the leaves on my plants look a bit nutrient deficient.

Thanks
Nick.

 

[mibson]

If it were me I would up the NO3 to around 20-30ppm, probably near 30ppm. And not worry about the PO4. Only at really high levels say over 10ppm does PO4 become a problem.

Plants need P and N in a set ratio, at the moment they have lots of P available to them but cant use it all as they cant get enough N. Increasing the N level will result in the plants being able to increasing their P usage. This might also bring the P level down a bit.

Sam

OK, will add more NO3. That makes sense that the PO4 isn't being taken up without enough NO3.

I wonder if that explains why I still get a bit of algae and some of the leaves on my plants look a bit nutrient deficient.

Thanks
Nick.

I have heard that the N to P ratio is 10:1 is this true? I have some minor algae issues and my N does get to 3-5ppm sometimes when the plants grow to fast (giant Val) perhaps N at 20 and P at 2 would fix this?

Thanks for any help (sorry for hijacking)