Nitrate overload

[Vivid-Dawn]

Ways to lower nitrates?

I’m getting slightly frustrated. My nitrates have been 40ppm or higher for the last month or so. I do water changes often... one week I tried doing a 10% water change every day. Then I tried doing a 20% water change 3 times a week (Tuesday, Thursday and Saturday). I don’t want to change more than 50% within 48 hours, since that might make another cycle start again.

Two days ago, I upgraded my 8 gallon tank to a 15 gallon tank. I didn’t cycle the new tank, because I used 6 gallons of the old water, plus put in a rock decoration (the only one I have), plus the old filter cartridge that’s been in the 8g tank for a good 4 months or so.
So, when I moved everything, it was basically the same except for 9 gallons of brand new water... which I figured would take care of my Nitrate problem. I figured wrong...
I would think that doing what would basically be a 50% water change would help. What else can I do to bring nitrates down?
Get rid of some fish maybe? I could give my husband back his zebra Danio, one of my guppies has a crooked spine and I should probably euthanize her anyway. I don’t particularly like my Molly, since I wanted a lyretail and the person at the store got a regular one for me... So I would keep the Albino Cory cat, a pair of Zebra Danios and a pair of guppies.
I could put more plants in, but they’d probably die. I don’t have enough light, or a CO2 generator, or any of that other fancy stuff. And I’m broke, since I just got a huge medical bill >_<

[DavidDoyle]

Test your tap for nitrates.

[Vivid-Dawn]

I did. The color was between 0 and 5.0 on the chart. I really think that's a wrong reading, but I didn't do anything different than when testing aquarium water...except it was cold. But I doubt that would make any difference...?
Also, the Nitrites was 0 (didn't change color at all!), and Ammonia test was "undetectable" too ...it got the vaguest hint of green, barely enough for me to consider it a definite 0.25

Also, I aerate my water for at least 12 hours after adding Amquel Plus and Novaqua Plus. Maybe that's what I'm doing wrong? It says it gets rid of Nitrates, but I assume it's not destroying them, but just doing a chemical change and turning them into something less harmful?

[MyraVan]

David's right, nitrate are often found in tapwater.

There are a couple of things I'd like to clarify. You wrote "I don’t want to change more than 50% within 48 hours, since that might make another cycle start again." As long as you use tap water conditioner to get rid of chlorine and chloramine, and have the new water at more or less the same temp as the old, you can change as much water as you like and it won't cause a cycle. The good bacteria don't live in the water, they live in the filter (and on the rocks & plants, but mostly in the filter), and as long as you have nothing in your new water that will kill the good bacteria in the filter, you won't lose bacteria, so it won't start a cycle.

Also, you wrote "So, when I moved everything, it was basically the same except for 9 gallons of brand new water... which I figured would take care of my Nitrate problem. I figured wrong..." You seem to be suggesting that you won't have nitrate accumulation in a properly cycled tank. But this is not the case, in fact the whole point of filtration is to turn nasty chemicals (ammonia & nitrite) into the much less toxic nitrate.

The only way to get rid of nitrates is through water changes or using plants. (Or I guess there might be some commercial nitrate absorber you could use, but this is something that would need replacing on a regular basis, so isn't a good long term solution.) Of course, as David points out, the water change method only works if you have less nitrate in your tap water than in your tank, which might not be the case....

[Vivid-Dawn]

I know Nitrates are less toxic, but I've read they can still be a problem if they're high and for long periods of time. When I test the water, the vial goes red immediately... I don't even have to wait the 5 minutes for it to get that way. It wouldn't be so bad if it was 20 or even 30, I guess. But it's 40 or higher, and I would assume that a month is a bit too long (considering fish can get sick so quickly).

And I did keep the old filter cartridge, because I knew it would have a decent amount of bacteria. I want to leave it in there at least a week, until my new filter gets it's own colony of bacteria. The gravel is brand new (the tank before was bare-bottom), so it'll have to grow some too...which is why I figured a cycle will start.

Of course, I've only lost one fish in the month, and it was a new Gourami. So I guess I shouldn't worry too much.

[MyraVan]

Originally Posted by Vivid-Dawn

And I did keep the old filter cartridge, because I knew it would have a decent amount of bacteria. I want to leave it in there at least a week, until my new filter gets it's own colony of bacteria.

I'd suggest leaving it in there for much longer than a week. I started a new tank by putting the new filter in an old tank hoping to grow a good colony of bacteria on it before putting it into the new tank. I had it in there for a bit over a week, and when I put it into the new tank, 3 days later I had a nitrite spike in the new tank! What had happened was that the ammonia -> nitrite bacteria had grown, but there was very little if any of the nitrite -> nitrate bacteria. So I'd leave your old filter in there at least 3 weeks, to grow a more complete set of bacteria on the new filter before turning off the old one.

[euRasian32]

You could get some low light or hard to kill plants.

Wal-mart has bulbs for 3 bucks, anywhere from 4-7 bulbs and 90% of them will sprout, and you can send the unsprouted ones back to the manufacturer to get new ones. I've seen dwarf lilies and hardy apontogen (spelling?). I haven't tried the lilies.

C

[DavidDoyle]

The Amquel+ may be the problem. I use the regular Amquel, and have for years. If you read the label on Amquel it tells you that is will make the most common ammonia tests unreliable. I suggest you check the label on the Amquel+ to see if this might also be the case for trites and.or trates.

[Damon]

Take a sample of your water to your LFS and have them test it. You can go from there. Nothing removes nitrates from water other than plants and waterchanges. If your tap has high nitrates, I'd suggest finding an alternate, constant water source. (Even a neighbor's water could be different)