0 nitrates, should I dose ferts?(I think it's lying)

[adeebm]

Okay, so this is the second time this has happened to me. My tank is fairly heavily stocked and planted(46gal in "my tanks" for info). I did a nitrate test today and it comes up 0. This happened to me before and so I dosed ferts to 15ppm and after more shaking and another test, it had showed over 40ppm. So I'm a bit wary this time. I shook the 2nd bottle for 10min, and the test tube for 2 min, and still 0. Should I dose KNO3?

--Adeeb

 

[neilanh]

Remind me what size tank, how much lighting, etc?

Unless you're dosing a full regime of ferts, or having algae issues, I don't recommend dosing hap-hazardly.

 

[adeebm]

46gal, 2x39W T5HO. I just started dosing dry ferts because my plants were dying and seachem costs $$$. I've been doing 50% PWCs weekly because of all the poop, so nitrates were low. It might really be 0, or my test might be lying. I think 10min of shaking should have done it tho.

--Adeeb

 

[mudraker]

API master test says shake the second bottle 1 minute only. I wonder if you shook it too much?

What kind of plants do you have? There are a number of aquatic plants that can eat nitrates up fairly fast.

 

[adeebm]

Well apparently theres some compound in the bottle that comes out of solution, so you have to shake it back in. And it kept reading 0, so I thought I'd shake it more. It can't make it worse

Plants: Amazon sword, melon sword, cabomba, some other swords, rotala indica, pennywort, and sagittaria subulata.

I dosed 5ppm KNO3 now, so if it shows ~5ppm tomorrow then I'll know it's working, and up my dosages.

--Adeeb

 

[mudraker]

Pennywort eats nitrates like crazy once it gets going.

Not sure about some of the others.

 

[carpus]

Something doesn't track here...

Makes no sense. Paraphrasing, with insightful modifications: "I have too much nitrogen in the water, so I do lots of PWC, and now my nitrogen is low, should I add nitrogen?"

Poop is a great fertilizer, better than nitrate additives because the poop degrades largely to ammonia, which is a preferred nutrient for many (most?) plants.

Plants can die for lots of reasons, consider em all.

I think your main issue should be balancing ammonia, not nitrates. If you are doing lots of PWC because you have high ammonia, you need to address that.

Whether your test for nitrate is working is not the primary issue.

46gal, 2x39W T5HO. I just started dosing dry ferts because my plants were dying and seachem costs $$$. I've been doing 50% PWCs weekly because of all the poop, so nitrates were low. It might really be 0, or my test might be lying. I think 10min of shaking should have done it tho.
--Adeeb

 

[adeebm]

No, I do not have high ammonia. My ammonia is 0, as it should be. I HAD high nitrates before because I wasn't fertilizing then, so obviosuly there was an excess of nitrates. Now I'm using ferts because my plants were in poor health, so I guess they're eating up nitrates.

My issue is whether or not the nitrate test is correct, because it has come up as 0 before when it wasn't.

And either way, I want to keep the poop levels down, because though ammonia is good for plants, its bad for fish, and if I just let the poop collect, I would start getting high ammonia levels eventually.

--Adeeb

 

[Faile]

Have you calibrated your test kit? Hobby grade test kits are notoriously inaccurate at measuring levels under 20ppm. To calibrate a test kit you need to test it against a known solution (preferably several different - perhaps 0ppm, 5ppm, and 10ppm) and find out how accurate your test kit is in determining the level of each.