Aquaponic Gardening

A Community and Forum For Aquaponic Gardeners

What does it mean when you have high nitrates. I have tested my water and i found the following using my API TEst kit

ph = 7.2 ppm

amonia = 0 ppm

nitrites = 0 ppm

nitrate is a dark red which looks to me like 80 ppm

what would it mean if it goes to a 160 ppm?

I have a total of 6 grow beds with the Chop 3 setup .

i do have 2 tote grow beds full of tomato plants and cucumbers 

and i am growing cantelope , hot peppers , sweet and Zuccini in the other grow beds

thank you

Views: 1926

Reply to This

Replies to This Discussion

it means you need more plants..

high nitrates aren't necessarly a problem, i've read studies that when nitrates are 400+ that some fry will have problems (specifically bluegill)


i know i read somewhere that if nitrates are too high that they can begin to reconvert to nitrites, but i can't find that paper at the moment..

I think it's a good problem to have. Consider a water change where you take the high-nitrate water to your outdoor dirt garden or plants. My orange tree is having best year ever and I credit it to *waste water from my tanks. It's free fertilizer, use it well.

I doubt those high nitrates will stick around, unless you're really overstocked. How many fish do you have? Size of grow beds? size of fish tanks?

Have you recently just cycled?  If so, then you are right on course.  If that is the case you can expect  your pH to start to drop as well.   It is not unusual to have rather high nitrates in the beginning, though at 80 yours are not screaming for adjustment.  Give it a little time and see what happens.  The biggest mistake people make is trying to adjust stuff to quickly.  Nature takes time.

Nitrates will not revert to nitrites, that is going backwards on the nitrification process. That being said, fish do not like nitrates, but are far more tollerant of it than the other toxins created by the system. I think a nice operating range would be around round 40 to 60 with occasional swings either way. The ultimate goal is to keep fish and plants on a rotation where you are always adding and removing both as they grow to maturity. Thus keeping a natural balance between nutrient production and plant growth to keep both sides of the system happy and healthy. 

you're correct about the nitrification process, but a chemical process can cause nitrates to be converted back to nitrites.. i can't find the paper now, but will look around

Depending on the setup, yeah, sometimes it does take a while. My nitrates were off the chart for first 8 months of my systems lifespan. I've finally gotten them to come down to 40ppm.

Scott Roberts said:

I doubt those high nitrates will stick around, unless you're really overstocked. How many fish do you have? Size of grow beds? size of fish tanks?

How many fish do you have in your system? And how many gallons is it? If you want to bring down the waste levels in your system, you can do a partial water change. Empty about 1/3 of your systems water and fill it up with clean water. Make sure it won't swing your system's pH too much for your fish though.

Reply to Discussion


© 2024   Created by Sylvia Bernstein.   Powered by

Badges  |  Report an Issue  |  Terms of Service