Ideal range of Nitrates in a Planted Tank?

Ozzie Boss

Fish Fanatic
Joined
Sep 28, 2018
Messages
83
Reaction score
4
I was wondering, is there an ideal range to have nitrates in a planted tank? I usually have around 20-30 ppm of Nitrates at the end of a week. Is this too much? Should I aim for a bit under 20? Perhaps using less ferts? It might also depend on the plants themselves.
~~~~
Plants:
Val
Crypts
Dwarf Lily
Amazon Sword
 

NannaLou

Fish Herder
Joined
Apr 5, 2021
Messages
1,362
Reaction score
1,235
Location
Chichester
I think the recommendation is for nitrates to be less than 20 ppm.
I have a heavily planted tank that also has emergent plants (peace lily and philodendron- although I’m just about to remove that as I’ve been told that if the roots are eaten/chewed they can be poisonous) my nitrates usually sit somewhere between 0-2.5 ppm. I’m interested to see if/how much they increase by removing one of the emergent plants.
 

Sunnyspots

Fishaholic
Joined
May 19, 2021
Messages
598
Reaction score
300
Location
Porthleven, Cornwall
It's certainly less than 20 for tanks with fish. Without fish, I don't know if it would really matter except for the risk of algae overgrowth.
 

Byron

Supporting Member
Tank of the Month!
Joined
Feb 25, 2009
Messages
18,585
Reaction score
10,149
Location
CA
Agree. In a tank with fish, nitrates should be kept as close to zero as you can. If you have no fish and just plants, it is solely a matter of providing adequate balanced nutrients of which nitrogen is one.

Freshwater fish are impacted by nitrates; the extent they are depends upon the species, the level of nitrates, and the length of exposure time. There are no tropical fish habitats that have nitrates anywhere close to what we have in aquaria (except for those who do maintain zero nitrates). My tanks have tested in the 0 to 5 ppm range for more than a decade; for all I know nitrates might be zero. I have fish and plants. A stable biological system in an aquarium is one in which the nitrates never increase from one water change to the next; keeping them as low as possible, and consistently at that level, is the goal.

Except in high-tech method planted tanks, there is no reason to add nitrogen/nitrates to an aquarium as in plant fertilizers. Most of us have low-tech or natural method planted tanks, where we have fish (maybe too many almost) and consider plants as aesthetical and beneficial because they help maintain clean water. The plants in these tanks do not take up nitrate except as a last resort; they prefer ammonia/ammonium as their source of nitrogen, which is why they are so beneficial. Floating plants which grow rapidly are often termed "ammonia sinks" for this reason--they can assimilate more ammonia than the fish and organic decomposition is likely to provide. But so long as ammonia is available, and if the other 16 nutrients are sufficient, and the light is sufficient, the plants will take up ammonia/ammonium exclusively.
 

Most reactions

trending

Staff online

Top