Zero nitrate in established tank?

[cellodaisy]

I just got my nitrite and nitrate tests and tested my 30g (one young 2.5" eastern painted turtle, 4 feeder guppies).

pH: 7.0*
ammonia: 0
nitrite: 0
nitrate: 0 (?!)

Zero ammonia and nitrite I was expecting because the tank is established, but zero nitrate? I followed the test instructions to the letter, including all the "vigorous" shaking. I shook that test tube like nobody's business. I do about 20% water change weekly, but the last one was 4 days ago. So, why no nitrate? I am having some significant algae right now and the only thing I can think of is that the algae is eating it all up. Is that even possible?

*For all the wonderful folks who helped me sort out my pH problem, the cuttlebone seems to be working. Yay! Next on the shopping list: gH/KH test!

[colinsk]

Plants use Nitrate as a nutrient. In my fish only aquarium I always have nitrates even with twice a week 33% changes. I am starting to plant plants to help control this.

[cellodaisy]

Yes, I know plants (including algae) use nitrate, I just find it hard to believe that the algae is taking in ALL of the nitrate. The only other plant in there is one very sad, very small java fern. (It was sad when I got it---not my fault!)

[jm1212]

with such a tiny turtle and 4 little guppies, the nitrate may be low enough to get eaten up by the algae.

[colinsk]

Yes, I know plants (including algae) use nitrate, I just find it hard to believe that the algae is taking in ALL of the nitrate. The only other plant in there is one very sad, very small java fern. (It was sad when I got it---not my fault!)

When I had a diatom bloom it pulled the nitrates to 0 for a week in my heavily stocked tank. As soon as the growth slowed it came right back. For people regulating nitrates with plant growth they have to grow lots of plant mattter. Which means lots of prunning.

[cellodaisy]

Okay, thanks. I was having a hard time figuring out how zero nitrate was even possible, but if you guys think it's a believable reading then I feel better. Zero nitrate is great, I was just worried I had a faulty test. Thanks!

[Egress]

I don't think I would trust those results just yet. I'd suggest trying it on a different aquarium, but based on your sig that might be difficult. Does the kit have an expiration date? I use Aquarium Pharmaceuticals kits, each bottle has a manufacture date on it. A local Petsmart was selling kits that were 5 years old, at that age they would range from questionable to totally useless.

[cellodaisy]

I don't think I would trust those results just yet. I'd suggest trying it on a different aquarium, but based on your sig that might be difficult. Does the kit have an expiration date? I use Aquarium Pharmaceuticals kits, each bottle has a manufacture date on it. A local Petsmart was selling kits that were 5 years old, at that age they would range from questionable to totally useless.
I'll check the bottles when I get home, but I just bought them from bigalsonline.com, so I would certainly hope they're not expired!

[avionics30]

Zero nitrate is not that uncommon in my experience especially with either low stock or plant growth (even algae). If you don't have live plants and are getting algae, I would check phosphate next. Your test set is probably right on target!

[severum mama]

I'd find it hard to believe, especially since IME turtles produce a ton of waste. Are you totally sure that you're following the directions for the nitrate kit to the letter? Other than that, I would suspect an expired/faulty test kit. It would suck if you just bought the kit and got an expired one.

[Squawkbert]

The critical shaking step is when you shake bottle #2...

[shawnhu]

To test the kit, just urinate in the ammonia test tube, and see if any ammonia show up. If none does, your kit may be bad.

I also think that a turtle usually produces a lot of waste, even for a 30G. API's test shows 5ppm Nitrate as a first indicator. If you shut off the lights for 2 days, and then re-test, you should get nitrates since the algae can't use the nitrates without light.

[cellodaisy]

I shook bottle #2 quite thoroughly.

I'm not worried about the ammonia test---it showed nonzero readings when I was setting up the tank and it did not come from the same source as the nitrite/nitrate test (though all are API). I'd love to try the blackout test, but I have to keep lights on for my turtle's health. I suppose I could move the feeders to the 5g and test that---essentially start a fish-in cycle, but move them back to the main tank if the readings get bad.

[grannylvsfish]

I have had zero before, even with new kits... do not worry.