I hadn't tested for nitrates since the beginning of fishless cycling...as soon as I saw that I was getting some, I stopped testing.

Now that I've had fish in for a week...I tested everything this morning just to check it all out.

Last water change was 2 days ago and EVERYTHING including nitrates this morning is 0's acrossed the board ..with the exception of PH being 7.6 of course. Is it normal to have 0 nitrates? I dont have any live plants in the tanks. Just the 3 platys, 2 mollies and apple snail

it's not normal to have 0 nitrates, but it's possible.

however the important thing to remember is that nitrate test kits are not very accurate, so the instructions should be followed very precisley and the readings should be taken as indicative at best.

The important ones to worry over (as you know) are ammmonia and nitrite, and our test kits for these are much more accurate. so providing those are holding steady at 0 then you can be confident everything's going fine.

I've a confession to make: I've only just bought a test kit since first setting up my tank 4 months ago (funding issues) and I've found the same thing. I tested once, then came back and ran two side by side (API liquid kit) and they're coming up 0, though I unless I'm going colour blind they're ever so slightly darker than the indicator card.

Thats put my mind at rest a little, with my pH readings I was beginning to think I had a dodgy kit.

Just a quick note, on the nitrate liquid test, make sure you really shake up bottle 2 for a more accurate reading.

I'll do that, I did it for a solid minute (with my girlfriend giving me grief for how energetic my technique was...) but I'll do another one later to be sure.

okayyyyyy....well that answered that for me LOL. I did the test wrong. I was trying to do it from memory since hubby through out my instruction book for my test kit...here I shook the TUBE for a minute after adding bottle 2 instead of shaking the bottle before adding.


retest shows nitrates at 40 ish I think....hard to tell between the red shades. How high should they be before changing the water again?

You sould shake the tube after adding bottle one for 30 secs and at the same time shake bottle 2 really hard for 1 minute then add the drops. After that shake the tube for a minute. Sounds like you are getting readings now though, I dont think nitrate should be above 40 though? Maybe try again and then do a water change?

If thats the API kit, I must have completely misread the instructions. Will try again later.

Yep that API, I hate doing the nitrate tests lol.

LOL, that's me too! I HATE doing the API Nitrate test because its so much more complicated.

API Nitrate steps:
1) 10 drops from vertically held Nitrate reagent#1 bottle into 5ml test water in tube (meniscus crossing white line)
2) cap and invert the tube 3 times with reagent#1 in it
3) set kitchen timer and vigorously shake reagent#2 bottle for AT LEAST 30 seconds (don't guesstimate)
4) 10 drops from vertically held reagent#2 bottle into same tube of test water
5) recap and very vigorously shake for AT LEAST a full timed minute
6) place tube in test tube holder and begin 5 minute period with kitchen timer
7) hold tube against white side of color chart and compare colors

(Emphasis in these came partly from customers chatting with tech help at API)

~~waterdrop~~

You missed one more:

8 - Stop using API nitrate test kit after it reads 160ppm on one sample and 0ppm on a second sample with both samples taken from the same tank at the same time and tested at the same time with the same kit.

Add to the above the fact it reads over 100ppm on pure RO + salt and it was just too much and my API nitrate kits have never been used since.

I am sure its not a case that you have 0 Nitrates all together its more that you don't have measureable NItrates ... BUT are you testing before or after water changes ... and Nitrates being 0 is a good thing.