Water Test Results 24Hrs After Adding Fish. Need Advice On Water Chang

[FlyingFish78]

So yesterday I added 6 Zebra Danios to my 240 litre tank and 24hrs later I did the first water test:
 
Ammonia - 0
 
Nitrite - 0
 
Nitrate - Around 100
 
PH - 73
 
I'm happy about everything except the Nitrate. My question is: What percentage water change should I perform? The test kit recommends 20% but I can't see it diluting the Nitrate that much at only 20%. Anyway, I want to do this ASAP so any advice is greatly appreciated.
 
Many thanks,
 
FlyingFish78

 

[KCB]

That's quite a high reading for just 6 danios in a 240 litre tank, what is the nitrate level in your tap water? It might naturally be that high.

 

[eaglesaquarium]

Without knowing your tap levels, we can't advise.
 
 
Those are very high nitrates for only 24 hours of fish being in the tank, so its possible you have high nitrates in your tap.    (With that said, a floating plant like mentioned in your other thread would be beneficial, as they can draw nitrates out of the water fairly quicky.)    If these floaters grow out of control, which they can with lots of nutrients.... you can merely pull out some every so often and discard.  Duckweed actually makes a good mulch for terrestrial plants.

 

[ech0o]

duckweed = probably the best nutrient exporter i know of

oh also if your nitrates are 100 out of the tap, i would put your local water company on blast....

 

[eaglesaquarium]

Well, personally, I don't put a ton of stock in the nitrate test... its a 'range' thing, not a specific value for me.
 
 
 
I am curious what test kit you are using.

 

[FlyingFish78]

I'm using the Nutrafin test pack, where you mix chemicals with the water and compare on a colour chart.

I just tested the tap water and it gives pretty much the same reading as the tank water.

Here's a pic. It's a bit blurry but the freshwater colour chart is on the left.

 

[ech0o]

Yea you will have to look into ways of manually lowering your nitrates, and doing water changes for you will actually be raising your nitrates instead of lowering them, like in most tanks.   In my own opinion, the 2 best ways of doing this are through bacterial denitrification, and the use of plants.   I have heard of a couple stories of people running an additional filter filled with Seachem De-Nitrate, or other dense denitrifying materials (porous rocks, bio-balls, dense ceramic) which will eventually host the anaerobic denitrifying bacteria that convert nitrates to a gaseous form and expel them from the tank.  This method is used regularly in saltwater tanks as the "live-rock" is the main filter and hosts the bacteria that gas off the nitrates, keeping them at extremely low numbers, the same would carry over to freshwater application.   Also like eaglesaquariums was saying, floating plants may be the most effective nutrient sponges and I think will drastically lower your numbers if you keep on top of removing excess growth, in turn removing the nitrates.

 

[eaglesaquarium]

Well, good news/bad news.
 
 
Good news, your fish aren't producing tons of nitrate.
 
 
Bad News, your tap water is unhealthy.... it would be worth calling the water company... I don't think 100ppm is legal.
Getting the level verified by the LFS might help.

 

[ech0o]

 
 
Bad News, your tap water is unhealthy.... it would be worth calling the water company... I don't think 100ppm is legal.
Getting the level verified by the LFS might help.

 
Oh yea like I said before, that level is EXTREMELY unhealthy.   If i were you I would stop drinking the water for sure.

 

[FlyingFish78]

Well, good news/bad news.
 
 
Good news, your fish aren't producing tons of nitrate.
 
 
Bad News, your tap water is unhealthy.... it would be worth calling the water company... I don't think 100ppm is legal.
Getting the level verified by the LFS might help.

 
I will contact them as soon as I'm sure that the level is actually that high and I'm not just mis-reading.
 

 

 
 
Bad News, your tap water is unhealthy.... it would be worth calling the water company... I don't think 100ppm is legal.
Getting the level verified by the LFS might help.

 
Oh yea like I said before, that level is EXTREMELY unhealthy.   If i were you I would stop drinking the water for sure.
 

 
I have! Since 1999 I've been drinking only bottled water because the stuff which comes out the tap is full of crap. I recently changed to buying spring water in glass bottles because of the recent scare about BPA which leeches from plastic bottles.
 
... But that aside, can you both take a second look at the picture and double check I'm not mis-reading the results. The freshwater chart is on the left. The bottom segment reads 100. The next one up reads 50 and the next reads 20. To me it looks like the reading is somewhere between 50-100. That's the problem with a colour chart: The result can be so subjective.
 

 

[eaglesaquarium]

Honestly, its nearly impossible to judge the colors on a chart versus the tube through a picture on the internet.  I don't suppose to try.
 
 
Generally I believe the suggestion for reading the color (not sure how Nutrafin suggests it) is to look DOWN through the tube and compare the color that way.  It may not be quite as high as you think, but its virtually impossible to tell in a picture.  Also, try to get your readings in natural light, far more reliable than indoor lighting.

 

[FlyingFish78]

OK so I've made the decision to order the API test kit instead as that appears to be far more accurate than the Nutrafin kit. Would you recommend this one yourself?
 
Update: I fed the fish for the first time today. All the food was gone in about 3 minutes. The bad news is that they appear to be changing colour! The white stripes appear to have been turning a pinky colour and the fish appear to be behaving a little aggressively towards each other. I'm tempted to think they're stressed (perhaps about high levels of nitrate...) They're not shoaling though so perhaps this is an indicator they're not stressed after all.
 
I'm sure Zebra Danios should be silver and black, not pink and black.

 

[b3cca]

Maximum permitted Nitrates in drinking water where i live is 10 ppm, so if you are using tap water I doubt it will actually be anywhere near 100 ppm !! 
from what I've read here the home liquid nitrate tests can be pretty innacurate sometimes
 
 
You can always get in touch with your water company or google them and get a recent print out of their water stats.
Obviously their testing methods and stats are far more accurate than our basic home test kits.

 

[eaglesaquarium]

That 10ppm is probably the Nitrate-N reading, rather than the molecule value.  The molecule value would be just over 40ppm.  (based on the mass of the molecule of nitrate NO3)... the test kit measures the molecule, not the nitrogen atoms... so that is something to keep in mind.
 
 
Looking at the picture, it might not be 100 and could actually be somewhere near 40ppm.

 

[FlyingFish78]

Hi and thanks for the replies.
 

Maximum permitted Nitrates in drinking water where i live is 10 ppm, so if you are using tap water I doubt it will actually be anywhere near 100 ppm !! 
from what I've read here the home liquid nitrate tests can be pretty innacurate sometimes
 
 
You can always get in touch with your water company or google them and get a recent print out of their water stats.
Obviously their testing methods and stats are far more accurate than our basic home test kits.

 
I think you must be right about the accuracy issue. I just checked my water company's website and tests for my area, conducted on 14/03/2013, indicate a Nitrate rating of 20.24 ppm.
 

That 10ppm is probably the Nitrate-N reading, rather than the molecule value.  The molecule value would be just over 40ppm.  (based on the mass of the molecule of nitrate NO3)... the test kit measures the molecule, not the nitrogen atoms... so that is something to keep in mind.
 
 
Looking at the picture, it might not be 100 and could actually be somewhere near 40ppm.

 
It's so hard to tell even if you're looking at the sample in real life. I ordered the API test kit instead. Thanks for all your helpful advice.