Acceptable Nitrate levels?

[acsrmjq]

Hi All,

Hoping you could help answer this question -in your experience what is the maximum acceptable level of nitrate in an aquarium? I have a 125 litre 'medium' planted community aquarium. Ph 7.6, temp 25c, ammonia 0 and nitrite 0. The tank has been running for 3 months and is fully stocked (only at 90% according to Aqaadvisor). Despite doing at least one 25% W/C per week (but often twice), I was getting frustrated that my nitrate levels were not falling below 40ppm (API master kit). Then I realised that I needed to also check my tap water and, well you guessed it, my tap water reads 40ppm. I have tried using Nitra-zorb but to little effect.

Given the nitrate levels of the water source, is 40ppm and acceptable maximum nitrate level or do I need to find another solution?

Thanks,

Matt


Matt Quish

 

[Linwood]

Well, if you are using 40 ppm tap water, I'm impressed you are only seeing 40ppm in the tank.

40ppm is awfully high for tap water. In the US (at least I think it is a federal limit) the maximum limit that a community can delivery is 10ppm.

Note that testing nitrates with the API test kit is really hard -- you absolutely must shake the 2nd bottle really hard for quite a while (I think it says 30 seconds) before dispensing, then dispense immediately, and shake the tube really hard for a full minute afterwards.

One of the reagents in the 2nd bottle is not water soluable, so getting the proper amount dispensed it is critical it be thoroughly mixed -- and it will quickly fall out hence the continuous shaking.

So it may be worth just being really sure you are seeing 40ppm.

If it were me, personally, I'd get some kind of filter for your water both for the fish and for you, if it comes in at a real 40ppm.

I'm too new to this to give an opinion on how much fish can take and stay healthy, but if you are starting at 40ppm you are probably over half way to "bad" out of the tap.

 

[Brookster123]

Depends on the stock really.. some fish wouldn't tolerate it very long. What's swimming in there?

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[darkhymn]

Do you have a local aquarium store that might sell you RO water, or really any water that isn't that nitrate heavy for cheap? It might be worth sourcing your water elsewhere and adding essential minerals to it from a bottle if you'd like to see those nitrate levels under control. From what I understand, 40 ppm is about the maximum "safe" amount of long term nitrate for your more typical, hardier fish. It may cause problems in more delicate fish. Also worth considering: nitrates promote algae growth.
In the long term, for your own health as well as that of your fish, start distilling your water or invest in a RO filter for your tap. Nitrates reduce red blood cells' ability to carry oxygen, and long term exposure can pose health risks. Unfortunately, levels up to 50 ppm are legal in the UK, so your local water company is under no obligation to decrease those levels.

 

[acsrmjq]

Hi all,

Thanks for getting back to me. Yeah I have heard that the Api test can sometimes be inaccurate if the bottle is not shaken enough. Incidentally I have also tested using strips and they say that my nitrate levels are 'safe' but I have read on here many times not to trust them. Although my tank water consistently reads 40 ppm, I have only tested the tap water once so will check again. I have had an outbreak of hair algae which is another reason I'm concerned by the nitrates.

The tank houses 6 Cherry Barbs, 5 Harlequin Rasboras, 3 Honey Gouramies , 6 Guppies and 3 Panda Cories. Would 40 ppm be ok for these species? Ideally of course I don't want to have to pay any more for RO water but I shall look into this if there is no other solution.

Cheers


Matt Quish

 

[Linwood]

I have had an outbreak of hair algae which is another reason I'm concerned by the nitrates.

I wouldn't assume much connection there, you can get it with very low nitrates as well; plus hair vs staghorn vs bba is often hard to distinguish.

Not saying ignore the algae, just don't trust that as a nitrate indicator.

 

[Caliban07]

Hi All,

Hoping you could help answer this question -in your experience what is the maximum acceptable level of nitrate in an aquarium? I have a 125 litre 'medium' planted community aquarium. Ph 7.6, temp 25c, ammonia 0 and nitrite 0. The tank has been running for 3 months and is fully stocked (only at 90% according to Aqaadvisor). Despite doing at least one 25% W/C per week (but often twice), I was getting frustrated that my nitrate levels were not falling below 40ppm (API master kit). Then I realised that I needed to also check my tap water and, well you guessed it, my tap water reads 40ppm. I have tried using Nitra-zorb but to little effect.

Given the nitrate levels of the water source, is 40ppm and acceptable maximum nitrate level or do I need to find another solution?

Thanks,

Matt


Matt Quish

Good question. I believe the answer is unknown for fish at least. I would tend to agree with Brookster that the effects will be more than likely species dependent. People claim that nitrate suppresses the immune response of fish. I've never seen any scientific data to prove this but I wouldn't discount it either. Then there are others who claim they have kept fish in nitrates in the hundreds and never had any problems but this doesn't mean the fish aren't suffering. I think as a general consensus to err on the side of caution 40ppm sounds like a reasonable limit and was more than Likely why this value is generally recommend. In stable tap water this isn't difficult to achieve.

In your case I would actually consider an RODI unit as already stated. You can cut your tap water with it to reduce the nitrates. Using live plants, feeding and stocking sensibly, and good filter and substrate maintenance with contribute towards keeping nitrates below the recommended level.

Good luck


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[acsrmjq]

Thanks for the advice guys.


Matt Quish

 

[PB_Smith]

For the stock you have 40ppm is not a real major concern. The only real effect may be a decrease in growth rate and shorter life span. but I doubt you will see any overt problems.
If you had rams or discus, the it would definitely be cause for concern.


Either way, you should take steps to mitigate any issues. Adding more plants may be all that is needed. Contact your water company/city or look up the local water quality reports and see what they say.
I believe they are done at least annually and are public record.