Question on Nitrate

cboatman

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Hi everyone! I've had my 10 gallon up and running for 5 months now. It's got 8 neons in it currently and a snail. It's pretty heavily planted with Anubis and some sort of stem plant and wisteria.

I got a new test kit and was doing some routine testing. I came up with 0 everything, including nitrates. Is it possible to have 0 nitrates or is the test kit faulty? I know for certain the tank is cycled, since it's been running without a problem for a while now.

Additional information: I do weekly 50-60% water changes. Because it's got a quite a few fish compared to its size, I put on a biowheel penguin 100 on it. The fish all seem vibrant and healthy.

Thanks everyone!


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Generally speaking, you're not supposed to be changing that much out each week. Normally it's less than 50%, but if it works, I guess it's fine. But, to answer your question, I'm pretty sure the answer is yes, if the aquarium is heavily planted and with water changes that large. After all, nitrates are the finishing product of the nitrogen cycle. Hope this helps.
 
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Yes it is possible but it typically isn't caused by the water change. Good plant growth will easily push the nitrates to zero. I see it frequently in my tank.
 
I agree with Steven. Assuming you do not have nitrate in the source water, then any nitrate in the aquarium will be what is naturally produced by the biological system. With good plant growth, and provided the tank does not have too many or too large fish, and they are not being overfed [i.e., organics are kept low], nitrates should be low, and may even be zero with our aquarium tests.

This has too reasons. Some plants do take up nitrate, but more importantly they take up ammonia/ammonium as their preferred source of nitrogen. This means there will be less ammonia/ammonium taken up by bacteria, and it is the nitrifying bacteria using ammonia/ammonium that results in nitrite and then nitrate.

Low nitrate is nothing to worry about. Fish are negatively affected by nitrate, it just takes much longer to cause death, but it can happen, and along the way the fish are weakened the higher the nitrate. So zero nitrate is very good for fish. My tanks tend to run between zero and 5 ppm nitrate, depending upon fish load in the specific tank.

Edit: Forgot the issue of water change volume, sorry. Keep up with the 50-60% weekly changes, that is perfect. I'm going to post directly to post #2 as I want to explain things a bit.

Byron.
 
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Generally speaking, you're not supposed to be changing that much out each week. Normally it's less than 50%, but if it works, I guess it's fine. But, to answer your question, I'm pretty sure the answer is yes, if the aquarium is heavily planted and with water changes that large. After all, nitrates are the finishing product of the nitrogen cycle. Hope this helps.

We have sufficient scientific evidence these days to be able to answer the question of water changes better than we could with as much degree of certainty several years ago. I'd like to offer some ideas to think about.

Pollution accumulates in an aquarium with fish on a regular and consistent basis. No filter can adequately deal with this pollution, except live plants but this is quite limited considering how most of us stock our tanks. Removing the "old" water and replacing with fresh is still the only way to deal with this issue. So that brings up the question, why do we need to do this in the first place?

Fish in their habitats do not live in the same water for more than a second, the time it takes to respirate once. The next "breath" they take will be "fresh" water. This is next to impossible to achieve in an aquarium, unless you have a flow-through system where water is flowing out at one end and being discarded (like, into the drain) and fresh tap water is flowing in at the other end continually. Even public aquaria can't usually have this, so we use water changes to get as close as we can. Because this exchange of water is crucial for the health of the fish.

The "pollution" that accumulates includes ammonia, though bacteria and live plants should be able to handle this. Then we have urine--a small tetra can void up to 1/3 of its body weight in urine every day; this urine is simply "stale" water, which is the tank water entering the fish by osmosis through every cell, being treated by the kidneys, and then expelled. Then there are chemicals like pheromones and allomones released by all fish. No filter can handle these (urine and chemicals) adequately if at all. Then there is the remnant of the solid waste the bacteria in the substrate and filter do deal with initially, but what is left behind dissolved in the water can only be removed via a water change. And there are trace minerals that need replacing.

Leave a glass of plain water to sit out for a few days. Then drink it, and drink water from a freshly drawn glass. You will see quite a difference. And there are no fish in this water, yet it is still being acted upon.

That brings us to the volume. This partly depends upon the fish load (number, sizes, and compatibility factors all factor in), water volume (tank size), live plants and filtration. The greater the load on the biological system, the more water needs to be changed. But rather than think of the minimum we should change, to avoid emergencies, it is better to consider how much we can change to keep the fish healthier. Prevention rather than treatment is always better for the fish, and easier for the aquarist.

When you remove a certain amount of water, you are only removing that percentage of "pollution." As a simple example, if we have a 10 gallon tank and the fish load adds a specific percentage of pollution--we'll give it a number so it is easy to fathom, say 100 ppm, removing 25% of the water is only removing 25% of the total 100 ppm pollution; the rest (75 ppm) remains. During the week, the fish add the full weekly amount of pollution, another 100 ppm, so at the next water change we now have 175 ppm pollution. Removing 25% of the water will this time remove 25% of 175 ppm, leaving 131 ppm of pollution. And the next week it increases again, and so on. So no matter what, the more water you change, the better for the fish.

Changing 10% every day for a week is not even close to the benefit of changing 70% once a week, due to the continujal increase explained above. So the larger the volume, the fewer times you need to do it. And even doing it more often, at smaller amounts, is not going to have as much benefit as doing one larger volume change each week.

Some discus breeders do two or three 95% water changes every single day. They can stock the "grow-out" fry tanks with more fry this way, and the fry grow faster and are healthier. The benefits of water changes really cannot be overstated.

I do 60% or maybe a bit more on each of my 8 tanks, every week without fail. This is the best way to ensure stable parameters, good water quality, and healthy fish.

Byron.
 
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Something else to consider is the nitrate test itself. If you are using the API Master kit (which is common, and I can't speak for any other test kit), the second bottle of nitrate test solution has a powder in it. This powder quite quickly settles out of the solution, which can lead to an incorrect reading.

The fix for this is to shake the absolute living daylights out of the bottle before performing the test. I believe the bottle says shake for 30 seconds, in my experience you need at least a minute (perhaps even two, if the test hasn't been used in a while), and you can even bang the bottle on a hard surface a couple of times. Once your arm is ready to fall off, you're ready for the nitrate test.
 
Thanks everyone for the advice! Ill definitely try shaking the bottle better. Could low nutrients be the reason my wisteria sort of started melting? It was growing great and then started dying from the base up. I clipped off all the decomposing parts.


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I retested after shaking harder and ended up with a reading of 5.0. Thank you for the suggestion!


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Thanks everyone for the advice! Ill definitely try shaking the bottle better. Could low nutrients be the reason my wisteria sort of started melting? It was growing great and then started dying from the base up. I clipped off all the decomposing parts.

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Nutrients can be a factor, but light is the usual cause of what you describe. Stem plants are fast growing, and naturally they grow toward the overhead lighting. Plants prefer to put their energy into new growth, so the older existing growth is generally the first to die off when there is a deficiency in light or nutrients. Here, the upper growth ends of the stem are closest to the light so they make more use of it. Less light is able to reach the lower portions of the stems, and when this is insufficient to drive photosynthesis in those leaves, they weaken and tend to die off.

Increasing the light intensity to compensate is not always feasible, as more light will mean more imbalance and may cause algae problems. And you mention Anubias, which is a slow growing plant and thus requires less light and nutrients; under too bright a light such plants are notorious for developing brush algae. Floating plants, or overhanging taller plants, can usually deal with this, but up to a point.

A better recourse would be to pull up the stems once the lower leaves have died, cut them below the good growth, and replant. This can be done as often as necessary, depending upon the growth habit of the plant.

Having said that, it is always possible that nutrients are insufficient, to balance the light which may be sufficient. Are you adding any plant additives now? If yes, which and how much and how often?

Byron.
 
I'm not adding any nutrients. The light I'm sure isn't a very good one and it was being shaded at the base. It seems to be doing alright now, that I've taken off the dead parts.


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I'm not adding any nutrients. The light I'm sure isn't a very good one and it was being shaded at the base. It seems to be doing alright now, that I've taken off the dead parts.


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Most likely this is the usual light issue I described. Another trick is to have chunks of wood or other plants (like the Anubias, tied to wood or rock) in front to hide the bare lower stems. Of course, eventually as the plant grows taller you will still have to do the pruning thing, otherwise the plant will continue to grow across the surface and shade the lower parts even more.

You might consider a comprehensive fertilizer. Stem plants need more nutrients to provide sufficient for their faster growth. Fish foods provide some, and water changes (I should have asked what your GH is, as the hard minerals in water are also important nutrients). Of course, if the Anubias is doing well, it might be better not to upset the applecart, so to speak, and consider different plants if the Wisteria does not live up to expectation. I have had this plant a couple times in the past, but it eventually weakened because I was not providing sufficient light and nutrients, but as the many other species were doing well, I had no intention of changing things so the Wisteria eventually got turfed as it reached the point when it was not doing well at all unless I just left it floating.
 
I currently have it just floating. If that's all it ever does, that's fine with me. I'll just need another plant to replace it. What is gH and where would I find it? Sorry for the ignorance. I'm on my cities annual testing results page and I can't find a reading for gH. Is it the same as alkalinity?


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I currently have it just floating. If that's all it ever does, that's fine with me. I'll just need another plant to replace it. What is gH and where would I find it? Sorry for the ignorance. I'm on my cities annual testing results page and I can't find a reading for gH. Is it the same as alkalinity?


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Alkalinity is also termed carbonate hardness or KH. It is related to the GH which is general hardness. Might also be called Total Hardness. This is the level of dissolved mineral in water, primarily calcium and magnesium, that determines the hardness of the water.

If you can't find it, and want to post the link to the page, I will take a look. Sometimes they hide these things.:hey:
 
Hardness according to the testing results is 19 mg/L.


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Hardness according to the testing results is 19 mg/L.


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OK, that is very soft water. 19 mg/l is the same as 19 ppm (parts per million), which equates to slightly over 1 dGH.

I have similar water, actually half (mine is 7 ppm) which is super for soft water fish and plants, but it does mean the "hard" minerals are missing. This will affect fast growing plants. I have got around this by using Flourish Tabs next to my substrate-rooted plants like swords, plus Flourish Comprehensive Supplement (liquid) for everything. You might find this helps. Anubias as I said is slow-growing, so less likely to show issues from very soft water with no additives, but some other plants will be better with some supplementation.
 

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