What can I do to increase Nitrate?

Ryan_M

New Member
Joined
Jan 3, 2022
Messages
6
Reaction score
0
Location
Courtice
I put some live plants in my tank but they're failing hard. Had a convo with a guy at the LFS and he said my water is the reason the plants were dying.... Using an API test kit my amonia, nitrite, and nitrate were all zero. He suggested I back off the water changes to allow the nitrate to increase to help the plants. Ive been adding a fertilizer as well but he suggested I let the nitrates get to 15-20ppm before doing water changes, and only top up for evaporation.

It's been 2 months since i did a water change now. Amonia and nitrite are still zero, the colour for the nitrate has changed a bit. Not as high as 5ppm which is the lowest colour band on the card, judgement call here but looks like 2, maybe 3 ppm. The plants still have a bit of green but are sickly and nearly dead. What can I do to help?
 
With plants in the tank, nitrate won't (or shouldn't) increase.
When there are no plants in a tank, nitrate increases because the fish make ammonia which bacteria turn into nitrite then nitrate.
Aquarium plants prefer ammonia as their source of nitrogen. They have to turn nitrate back into ammonia to use it so it takes less energy using ammonia directly. Plants turn ammonia into protein not nitrite or nitrate so if the plants take up all the ammonia, there will be no increase in nitrate.

Reducing water changes allows things to build up in the tank, waste products we can't test for. And it means that nutrients in the water get used up as they aren't being replenished by new water.


Plants usually die because the light is not the right type; or they don't have the right nutrients. They need a lot more than just nitrogen. Nitrogen, phosphorus and potassium are the macronutrients, but there are something like 13 other elements needed by plants, the micronutrients.
 
Hmmm strange issue as if your plants are not growing it means they are not taking up the ammonia in the water and your filter is doing all the work - in this instance (unless the tank is set up for anaerobic bacteria) you would end up with nitrates.

Your plants should be feeding mainly off ammonia from the fish, which in that natural process you don't end up with waste products like nitrite and nitrate, as you would expect from a bacterial filtration process.

Can you post a picture of your tank and let us know what fish you have in there? Also just to check when you do the nitrate test do you shake the bottle and the tube like crazy? You have to really go for it to get an accurate result - especially the test bottle, I believe it has 2 chemicals in that separate over time so you have to shake it to mix them.
 
What sort of light is on the tank (include temperature/ Kelvin rating of globes/ LEDs)?
How long is the light unit on for each day?
Do you get any algae growing on the glass, plants or ornaments?

What fertiliser do you use?
How often do you dose it and how much fertiliser do you use?
Do you test for the fertiliser in the water?

What sort of plants do you have?
Post a picture of the entire aquarium so we can see the plants.

---------------------

If you have garden plants they won't do well underwater. Lack of light will kill them. Lack of nutrients will slow their growth. Lack of nitrates won't really kill a plant, certainly not quickly.

If you want to increase ammonia and possibly nitrate, feed the fish more often. Just make sure you do regular gravel cleaning and water changes to dilute the microscopic organisms that will grow from the extra food and fish waste.
 
I put some live plants in my tank but they're failing hard. Had a convo with a guy at the LFS and he said my water is the reason the plants were dying.... Using an API test kit my amonia, nitrite, and nitrate were all zero. He suggested I back off the water changes to allow the nitrate to increase to help the plants. Ive been adding a fertilizer as well but he suggested I let the nitrates get to 15-20ppm before doing water changes, and only top up for evaporation.

It's been 2 months since i did a water change now. Amonia and nitrite are still zero, the colour for the nitrate has changed a bit. Not as high as 5ppm which is the lowest colour band on the card, judgement call here but looks like 2, maybe 3 ppm. The plants still have a bit of green but are sickly and nearly dead. What can I do to help?

This advice is not only false but dangerous to the fish. All fish are detrimentally affected by nitrate. It is now understood that nitrate slowly weakens fish, making them more susceptible to disease and shorter lives. Keeping nitrate as close to zero is always beeneficial to fish.

As for plants, this is utter nonsense. First, as @Essjay said, aquatic plants take up ammonia/ammonium. They do this faster than the nitrifying bacteria/archaea. They do not produce nitrite nor nitrate in the process.

It may be that there is insufficient ammonia/ammonium for the plants, but this is highly unlike if there is a normal fish load and they are being fed. Not only does ammonia occur from respiration of fish, it is also occurring from the breakdown of organics in the substrate. Fast-growing plants will rapidly consume this. It is more likely there is an issue with light or the other nutrients, depending again upon the fish stocking.

The mor water changes you do, the healthier will be the fish, this is proven science.
 
No matter how many plants one hasm there will also be some number of nitrifying microorganisms at work and some amunt of nitrate will be the result. The reason for this is nost tanks have some amount of ammonia as NH3 and the bacteria will take some of that up, The plkants will get anything else as NH4. Some plants transport oxygen down into their roots in anaerobic sones in the substrate. There they release it. And the result is nitrifying bacteria colonize. That is followed by anaerobic zones bot above and below whichuse the nitrate created . The pants will get ammonium from all of this via their roots.

When I ran my high tech pressurized CO2 tank I used to dose Potasium Nitrate to elevate nitrate levels some. In a tank with fish and plants we cannot add ammonia, So the have to feed the plants Nitrogen other ways. It is hard to see what provides the Nitrogen in Flourish on the SeaChem site, but they do list the ingredients for Flourish Nitrogen which are>

Ingredients
Amounts per 1 g
Total Nitrogen (N)1.5%
Soluble Potash (K2O)2%
Derived from: potassium nitrate, urea
from the FAQ here https://www.seachem.com/flourish-nitrogen.php

We often seem to forget that the amount of ammonia being created in a cyelced tank on an ongoing basis will never be detected by our test kits. The reason is simple- the bacteria and/or plants will use it almost as fast as it is being created. This is why it cannot accumulate. And in a tank with the right kind and volume of plants, any nitrate the bacteria do create is also consumed similarly.

Global urea production capacity is ≈220 million t/year. Why is urea produced in such large quantities? The answer is that, other than ammonia, urea has the highest nitrogen content of all industrial chemicals and is in high demand as a fertilizer. In the soil, it decomposes back to ammonia (actually ammonium ion) and carbon dioxide. Nitrogen-fixing bacteria oxidize ammonium to nitrate, which is readily taken up by the roots of crops. In addition to its high nitrogen content, urea is particularly useful because it can be applied as a solid in pellet form; and its unusually high solubility in water allows it to be incorporated into solutions with other plant nutrients.
from https://www.acs.org/molecule-of-the-week/archive/u/urea.html
 

Most reactions

trending

Back
Top