Is zero nitrate.....a bad thing?

Ok, so I buy 6 fish from my lfs, 2 days later one goes belly up. I test the water, Ammonia 0, Nitrite 0, Nitrate 0.
I goes back to lfs with said fish & water sample. They test water then look at me suspiciously when nitrate reading is 0. He says its very unusual for nitrates to be 0. He gave me a credit note, but with a sideways look.
I thought the aim was to have three zeros.
Its a reasonably well planted tank, & I assume the plants are globbling up all the nitrates. Surely it isn't THAT unusual to have zero nitrate?
Also, I have absolutely no algae growth, (which I'm sure my bristlenoses arn't too happy about!), which I guess is down to the zero nitrate?

in a fully cycled tank the ammonia should be 0, Nitrite should be 0 and Nitrate should be somewhere between 10 - 40ppm. To have a reading of 0 Nitrate means there is no nitrifying bacteria in your tank which will cause you problems.

was the tank fully cycled before adding the fish? if so have you done anything different lately apart from adding the fish? Have you cleaned the filter out recently

Now I'm worried ...The tank's fully cycled, it's been running for a few months now. I cleaned the filter 2 weeks ago. The only thing I've done recently (3 days ago) is add another internal filter. Nitrate reading 2 weeks ago was 20 ppm, & 1 week ago <10 ppm & today 0 ppm

0ppm Nitrates

Hi all,
ST24rsap is right, it's almost impossible to have 0 ppm nitrate in a matured tank, even a very heavily planted one. If the tank hadn't been set up for long? I'd bet that this was a nitrogen issue.

This is partially why I don't like "cycling" tanks or unplanted tanks for sensitive fish, it is much safer to set a tank up, plant them and then leave them until a healthy plant growth and biofilm build up, at that point the whole tank is acting as a biofilter, rather than relying on just the bacteria in your filter. You can still do this if you keep Gibbies, Pacu, Mbuna, Silver Dollars etc., you just need the plants in the filter, rather than the the tank.

I really liked this thread, and that would give you a movable plant and biofilm "module" that you could put in any new tank to help the stabilization process.
<http://www.plecoplanet.com/forum/showthread.php?t=656>

The 2' tanks I keep my Apistogrammas in are lightly stocked, overfiltered with huge sponge filters, have a silica sand substrate, lots of light, very heavily planted (including plenty of floating plants), 10% water change (rainwater) every day (and no plant feeding), and at the moment only live food. They will still have about 10ppm nitrate, and the only way to get below this would be a larger water change with R.O. water. Most tap water in the UK has at least 10ppm nitrate, the legal limit for drinking water here is 50ppm, and a lot of tap water will be in the 30 - 40ppm range.

cheers Darrel

Thanks for the replies...Strangely enough i loved that thread too & have about 15 java ferns stuck on the back, it's a great idea!....ok sorry if I'm being a bit thick, but how do I resolve my problem?

Smeagol said:

Now I'm worried ...The tank's fully cycled, it's been running for a few months now. I cleaned the filter 2 weeks ago. The only thing I've done recently (3 days ago) is add another internal filter. Nitrate reading 2 weeks ago was 20 ppm, & 1 week ago <10 ppm & today 0 ppm

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After reading your thread I dont believe there is much wrong as the nitrates have reduced over the months, and it will be due to the plants. If the tank was not cycled the ammonia level would be rising and its not. My best advice is to keep an eye on things for the time being.

Btw 0 readings will not kill fish so it was not that that caused the fish deaths

Hi all,
Smeagol, sorry I misread the original post, I thought it was all 6 that had died, not just the one. As the other posters have said the tank sounds fine. I would expect the nitrate levels to return to 10 - 20ppm, possibly as the second filter matures.

If you want to see if adding some nitrate would have any effect, you could try adding a small amount of potassium nitrate solution (You can work out how much you need for your tank to give 20ppm (using the volume), but realistically 1/2 a teaspoon of powdered potassium nitrate should give you a visible response unless the tank is absolutely huge), but I'd only try this if your plants stop growing all together and the nitrate reading stays at 0ppm.

cheers Darrel

Thanks Darrell ,
It's a 6'x18"x18" tank. Plants are growing like mad & all other fish are thriving, so I think I'll wait & see & just keep testing,
Thanks for all replies :clap:

good luck, keep testing and doing some small w/c every other day.
might help to tell us a bit more about your water?
do you use conditioned tap water / rain water/Ro ?
i assume you clean your filter with used tank water and not tap water?
nice size tank! you dont mention what type of fish you bought. (some are more sensitive to others and some will suffer from the stress of the move and the settling into different water etc)
do you have any other tanks or just the one? any other fish in the tank?

D-MAC said:

After reading your thread I dont believe there is much wrong as the nitrates have reduced over the months, and it will be due to the plants. If the tank was not cycled the ammonia level would be rising and its not. My best advice is to keep an eye on things for the time being.

Btw 0 readings will not kill fish so it was not that that caused the fish deaths

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:yes:

Plus Nitrate test kits can be hit and miss on accuracy. I would get the tap water tested, so that you have a base reading.

Another option would be a TDS meter.

Irene0100 said:

good luck, keep testing and doing some small w/c every other day.
might help to tell us a bit more about your water?
do you use conditioned tap water / rain water/Ro ?
i assume you clean your filter with used tank water and not tap water?
nice size tank! you dont mention what type of fish you bought. (some are more sensitive to others and some will suffer from the stress of the move and the settling into different water etc)
do you have any other tanks or just the one? any other fish in the tank?

Click to expand...

Lots of questions!:lol:
Ok here goes...
I use conditioned tap water.
Yep, I clean filters with used water.
I bought 6 Boesemani Rainbows to add to my 18 Blue Rainbows (Melanotaenia Lacustris). I also have 6 Dwarf Neon Rainbows, 10 Congo tetras, 8 corys (4 albino, 4 peppered) 3 bristlenoses...oh yeah, & one 2" blue phantom.
I also have a 4' tank with 20+ mollies & 7 zebra loaches.
Plus a 3' tank with 8 zebra loaches, 4 harlequins & 5 glowlight tetras (both courtesy of Gooner & Bubbles), 6 neon tetras & a few more mollies.
Think that covers everything! :woohoo:

Doodles said:

:yes:

Plus Nitrate test kits can be hit and miss on accuracy. I would get the tap water tested, so that you have a base reading.

Another option would be a TDS meter.

Click to expand...

Sorry I'm a bit thick...TDS meter? Wots one ov them then?:huh:

Smeagol said:

Sorry I'm a bit thick...TDS meter? Wots one ov them then?:huh:

Click to expand...

This may help
http://www.tdsmeter.co.uk/abouttds.html

It measures total dissolved solids. You first test your tap water for a base reading and can monitor your tank water. It doesn't tell you if you have ammonia, nitrite or nitrates but is a good way to see how much build up of waste there is. High TDS become bad for the fish and breeding.

Anyway check out these links for more detailed info

http://en.wikipedia.org/wiki/Total_dissolved_solids

http://www.tdsmeter.co.uk/abouttds_aquaculture.html


My water is really hard so i have a fairly high baseline, around 300 but i do water changes twice a week and keep that number as close to 300 as i can.

lol ya beat me

That's great, thanks for the info

Hi all,
Something is strange, because the combination of "Milton Keynes" tap, the fish (nice choice of fish though), and the fact that the plants are growing like mad means that you will definitely have some nitrates in the water, if you didn't the plants wouldn't grow.

If you do get a meter, I think your TDS reading will be quite high, mainly because the water going in will have quite a lot of carbonate minerals (hardness) in it, that isn't a problem on its own but it may stop soft water plecs spawning successfully.

Our tap water comes straight out of the limestone which makes it good for nitrates, but hard, about 14 dH.

cheers Darrel

Rainbows

Hi all,
Should also have said your Rainbows look really good and healthy in your gallery, particularly seeing from the other thread that some weren't great when you bought them, which would also suggest your water is good quality. The Blue Rainbow is very nice. Most Rainbows like hard water so that wouldn't bother them, same with your Mollies.
cheers Darrel

You've already gotten a lot of good help but as a side note, you're playing with fire by introducing new fish straight into your tank without quarantining. The new fish could easily introduce a disease to your tank and with the size tank you're dealing with & the plants could make it difficult & costly to treat.

Whenever fish die within a few days of introduction into a tank I usually look at it being an acclimitization issue.

Lornek8 said:

You've already gotten a lot of good help but as a side note, you're playing with fire by introducing new fish straight into your tank without quarantining. The new fish could easily introduce a disease to your tank and with the size tank you're dealing with & the plants could make it difficult & costly to treat.

Whenever fish die within a few days of introduction into a tank I usually look at it being an acclimitization issue.

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Yep point taken, I have a spare 2' tank that I will use for quaranting in future