trouble getting my nitrate lower

[Richard Ivory]

i have a 290 litre (about 60 gallons ) my tank is nearly 6 months old ,but i am struggling to get my nitrate down seems to be stuck at around 50ppm i have added 260 ml of npx bioplastic pearls about a month ago, building up to the 260 ml over 4 weeks o help but nothing as yet , i feed 2 frozen cubes a day

here are last sunday's test's as i test every sunday and i use NSW and do a 10% water change every week ,have 10 fish also

nitrate 50
salinity 1.025
alk 7.3 raised my dosing as want to keep around 8
calcium 410
mag 1290

 

[OutsideBrian]

What are you using / doing for nutrient export?
I have a similar sized tank, not as many fish but two cubes seems like a lot. One makes a mess of my tank. Maybe try one a day and some flake as a second feed?

 

[Richard Ivory]

What are you using / doing for nutrient export?
I have a similar sized tank, not as many fish but two cubes seems like a lot. One makes a mess of my tank. Maybe try one a day and some flake as a second feed?

yes will try that from tonight for a week to see if it moves ,i have a clarisea 3000 roller mat filter a protein skimmer and the bio balls

 

[Justfebreezeit]

Might want to test your phosphates. I doubt they are zero based on your load but it could be limiting your nitrate reduction.

 

[dwest]

i have a 290 litre (about 60 gallons ) my tank is nearly 6 months old ,but i am struggling to get my nitrate down seems to be stuck at around 50ppm i have added 260 ml of npx bioplastic pearls about a month ago, building up to the 260 ml over 4 weeks o help but nothing as yet , i feed 2 frozen cubes a day

here are last sunday's test's as i test every sunday and i use NSW and do a 10% water change every week ,have 10 fish also

nitrate 50
salinity 1.025
alk 7.3 raised my dosing as want to keep around 8
calcium 410
mag 1290

Make sure you have measurable phosphates. If you are using gfo or other phosphate removing materials your system may be phosphate limited such that nitrates will not be consumed.

 

[Richard Ivory]

Might want to test your phosphates. I doubt they are zero based on your load but it could be limiting your nitrate reduction.

they are 0.03 and confirmed by a icp test

 

[Richard Ivory]

Make sure you have measurable phosphates. If you are using gfo or other phosphate removing materials your system may be phosphate limited such that nitrates will not be consumed.

i run rowaphos should i turn off for a week ?

 

[dwest]

i run rowaphos should i turn off for a week ?

Yes. Then leave it off. It will likely take at least several months for your system to equilibrate. I bet, at that time, you will see you nitrate levels drop naturally.

 

[Richard Ivory]

Yes. Then leave it off. It will likely take at least several months for your system to equilibrate. I bet, at that time, you will see you nitrate levels drop naturally.

thank you