Nitrate Levels

[new fish lover]

Help, I don't know what's going on. In my 150 gal. we changed the water last weekend.

Water Change: Approx 25 % last Saturday

Filters: Tetratec 500 (with biofoam)
Emperor Penguin 400 (2 biowheels).

We have 4 filter media inserts in both filters. We changed 2 filtermedia in each unit on Monday.

Water Test: Prior to the water change our Nitrate level was at 10. Now our Nitrate level is at 20 or a little more. Ammonia 0-.25 (it looks pretty close to 0 but it's hard to tell. not really any tint of Green). Nitrite 0.

We added 2 Juvenile red swordtails last weekend when we changed the water. We only add fish approximately 2-3 weeks apart. So no other fish had been added for approximately 2 weeks before adding the red swordtail.

Lighting: We also added 2 fairly new light bulbs to the lighting. (Before our light bulbs were pretty old).

My possible theory is we over cleaned and disrupted the bacteria colonies and this has caused a nitrate spike. But is was at 10 even before we touched it.
What can I do about the Nitrates. I know a water change may help but for the future is there anyway to control the Nitrates??

Please let me know if you have any ideas?

 

[rvm]

20ppm of nitrates is nothing to worry about. Have you checked your tap water nitrate level? Mine sits between 40ppm and 60ppm.
I wouldn't think you have disrupted the bacterial colonies too much by replacing the media. How long was the tank set up before this? I would keep an eye on the levels over the next few days, but as long as the ammonia and nitrIte don't spike, then you should be OK.

 

[CFC]

Disrupting bacteria colonies wouldnt cause nitrAtes to rise as nitrAtes are the end product of the nitrogen cycle, are you sure you dont mean nitrIte?

Rising nitrites are a sign that the biological filtration in your tank is working and that the ammonia created by the fish has been converted to nitrite and then nitrate, the nitrates will have to be removed by weekly water changes or used up by live plants. Whenever possible try to keep nitrates below 40ppm though levels are not considered dangerous to fish until they reach above 80ppm

 

[new fish lover]

Thanks for the info. NitrAtes are my only problem at this time. I will continue to be ever vigilent on the ammonia and nitrite to make sure they are not a problem.

I just wish I could figure out a way to keep the nitrate down. Because I eventually would like to add more fish.

 

[Slyspy]

Get some plants. My little tank has been full of fish for two weeks now and the nitrates have not increased at all (though I did do a water change just in case). This I put down to the plants using most of it up. Ammonia nil, nitrites nil and nitrates steady at about 20ish, which is more or less the base amount in my local water. So far all my fish have survived *touches wood just to be safe*

 

[kev_kb]

As already mentioned Nitrate is the last product of the cycle, and 20ppm is nothing to worry about. If you have no plants the Nitrate will just keep building up, but you'll remove some with your weekly water changes so its shouldn't be a problem at all. If you have plants then they will use all/some of the Nitrates, but you should still be doing weekly water changes.

When the Ammonia and Nitrite levels are at 0 you are fine to add more fish, just do it slowly.