Frustrated

[patpaugh]

Ok, so here is my problem,
I have been cycling a 33 gallon tank for a while now. Everything goes alright right up until the end, and then all the sudden the nitrate has dropped to 0. This has happened about 3 times now, I add enough ammonia to get it back up to 4 ppm, nitrite spikes the next day, nitrate seems to be around 80 and then the next day everything is back to 0 again. This is the first tank I've attempted to cycle so hopefully someone can help me out.

 

[tom91970]

Give it time....by "for a while now" exactly how long have you been cycling the tank?

 

[Fuzz16]

do you have a filter on the tank?
any fish living in it?

 

[epond83]

... any plants?

 

[patpaugh]

I've been cycling the tank for 3 months now, 2 little plants in the tank, and a Marineland Penguin bio-wheel filter 200. Added Ammonia to get it from 0 to 4ppm at 8am checked it at 10 pm today and ammo is 0, nitrite is around 1 and nitate is around 30. Started out the day with 0 for all.

 

[MissFishy]

Um, folks...that means the tank is cycled!!!

If it is eating up your ammonia, that means the tank has cycled. Do a large 50% water change and add your first fish. Only one or two though, then keep an eye on the parameters.

 

[tom91970]

Why would the nitrate go back to 0? It is my opinion that once the ammonia and nitrite levels fall and the nitrate levels rise the tank is fully cycled. His nitrate level rises, but then goes back to 0.

 

[MissFishy]

He adds a lot of ammonia, nitrite levels spike as the ammonia is eaten up, next the nitrate levels spike as the nitrite is eaten up, next the nitrate is eaten up by the plants in the tank. Since there is no constant supply of ammonia (i.e. fish) the levels aren't stabilizing. If fish were added, the ammonia levels would be constant.

Of course, make sure you are dechlorinating your tank water, if you do not treat the water before adding it to your tank, the chlorine may kill off your good bacteria.

 

[FroggyFox]

I doubt that two little plants are getting rid of that kind of nitrate that quickly, but I do agree that the tank is cycled. I think I would test your nitrate test kit...some of them go bad after awhile, or there may just be so much nitrate in your tank that the kit is freaking out. I'd do your huge water change and add your stock!

The fact that you can see the levels changing means that your bacteria levels are healthy and ready to go.

 

[patpaugh]

Thanks for the input. the reason I was frustrated is because I thaught the tank was cycled, but the nitrates dropping back down to 0 confused me. I'll do a water change and get some fish.