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Hello hobbyists,

Have any of you had nitrate levels in planted tanks at 20-40 ppm and not have any problems?

My current tank is planted with crypts everywhere and nitrate level is 40 ppm.

Ammonia - 0 ppm
Nitrate - 0 ppm
Ph - 5.8-6
20 gal. long

Only fish are 9 rummy-nose and are doing good.

Just wondering
 

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There is a bit of debate in the hobby about what constitutes high nitrates in the aquarium and whether or not they are harmful. However, experts seem to agree that nitrates should be kept as low as possible, at least below 20ppm.

High nitrates lower fish immune systems such that stress can result in any number of illnesses that would not otherwise take hold. High nitrates also reduce life spans. Now some species seem to be more sensitive to high nitrates than others.

The easiest way to keep nitrates low is through routine partial water changes. Routine partial water changes also removes/replaces 'polluted' water with fresh clean water and replenishes necessary minerals used by fish and plants.

There are many that don't do water changes often enough (or at all) and claim their fish are fine. 'Old Tank Syndrome' results with poor water conditions and to a point, fish can adapt and survive to a point. But these same people often have fish that don't live very long and think that's normal or attempt to add new fish that simply can't tolerate the bad water.

Now I believe that there is a caveat here in the difference between a fish only and a planted tank. Plants can go a long way in purifying water in both nitrate removal as well as other impurities. This can extend (but not necessarily eliminate) the period or the water volume of the routine partial water change.
 

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Have any of you had nitrate levels in planted tanks at 20-40 ppm and not have any problems?

My current tank is planted with crypts everywhere and nitrate level is 40 ppm.
As you are going to find out, there are a wide variety of opinions about Nitrate levels.

I can only speak from my personal experience. The Nitrates in my heavily stocked Rainbow tank get up to about 60 to 80ppm before my regular weekly water change. I have some fish that are ten years old.

I worked really hard to get my Nitrate level down recently, and the only noticeable difference was that my plants did much worse.

If your fish and plants are healthy, I wouldn't worry too much about it.
 

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I have a relatively new 55 setup (about six months old) and it's only partially planted, with just a few small and medium sized plants (so far). However, one of the filters on it is from a very "seasoned" aquarium, so I have never had a problem with starting the nitrogen cycle going. However, while my my ammonia levels are always at <0.25ppm and nitrites are always at 0.0ppm, I can only keep my nitrates below 40ppm with weekly 50% water changes. I recently bought a bunch of fish at Petco's 50% off sale a few weeks ago, and although I moved two large plecos from that tank to a different tank (actually lowering the bio-load of the tank despite the many added smaller fish), the same readings continued, and I lost some black neon tetras and a rainbow. I suspected it may be that they were not accustomed to the higher levels of nitrate, which weakened their immune system and they succumbed to an Ich infestation of their gills. (I say the gills because, while there were very few spots on the black neons first--mostly on their fins--and then on other fish, I don't think what was visible was enough to cause mortality.) Of course, I did a heat & salt treatment on the whole tank and got rid of it (my own fault for not quarantining new fish, right?), but I suspect it was the higher nitrate level that was the underlying cause for the initial stress on the new fish. From now on I will be checking my nitrates and doing a significant water change before adding new fish (AFTER quarantining them, of course).

Although I have been out of the hobby for a long time, I consider myself a relatively experienced aquarist, but I don't recall ever having this much trouble with nitrates before. Maybe I've just forgotten about it, but I'm hoping that as I add more plants and they begin growing well, they will take care of the nitrate "problem".

The bottom line is that without other stress factors being apparent, I can only suspect the higher nitrate level as being the cause that stressed the black neons (who weren't used to it) to the point that they succumbed to the ich (which most likely came in with them or the other new fish in the first place). Had they been accustomed to the higher nitrate levels to begin with, I don't think there would have been a problem, since I carefully and slowly drip-acclimated all the new fish. Also, since the majority of the other species didn't suffer such a high mortality rate (just the one rainbow), I suspect that either black neons are more sensitive to higher nitrate levels or they are more vulnerable to ich.

That's just my recent experience regarding nitrate levels, so take it for what it's worth. (2 cents?)

Olskule
 

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For the past 18 months my nitrate levels have tested high, 60 - 80 ppm using an API test kit. Even after large water changes (50%) the test results would be in the red zone. I have a moderate to heavy planted tank with lots of fish(including black neon tetras), use PPS for ferts, and inject CO2. I have had no issues with losing fish, the majority of my fish have been in the tank for over a year or longer. In spite of not losing any fish I thought it best to try and get the nitrates down, < 40, into the orange on the API test chart. It took some time but I was able to finally get there. I did 25 - 30% water changes every 2 - 3 days until test results were orange. I also removed KNO3 from the PPS recipe. It's only been 2 weeks since making these change but now my nitrate levels seem to be under control. The only ill effects so far are the tips of my vals have turned yellow, although I did trim them during the run of water of changes. Time will tell if this change was an improvement....
 
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