Nitrates high after cycling

[Slickdonkey]

Hey everyone,

My tank has pretty much finished cycling. Ammonia is at zero, nitrites are at 0.1 mg/L, but my nitrates are > 100 mg/L!

Is this normal? I started a month ago with 240 pounds of live rock, and about 275 gallons of water. No fish or inverts, just live rock.

I was thinking of doing a massive water change, but will the high levels just come back? That's a lot of salt so I don't want to do it until I understand what's going on.

I've removed my filter sock; doesn't seem to help. It was changed regularly anyway.

 

[Detri]

Well, your cycle isn't done yet my friend. Sorry to be the barer of bad news. Depending on the rock a cycle can last more than 8 weeks. Your nitrates shouldn't be that high though. (I don't think anyway) I would get a new kit, Salifet or Seachem. Your test kit maybe bad. It is normal to have high Nitrates on the down stroke of a cycle. It is part of the cycle and a good sign your cycle is going to end soon. I would put your filter sock on only when you blow off your rocks and take them off when the water clears. Run your skimmer as per normal.

Start doing a weekly 10% water change. If your Nitrates don't start to drop. Change to a daily water change. 10% should be fine. If that doesn't work. Throw out your tank and equipment and start again. you bought some garbage. KIDDING. As everyone will tell you patience is key

 

[steve-s]

I would get the test result verified but it could very well be correct.

Actually the level of nitrate isn't relavent to the initial cycle process. Agreed the cycle isn't over yet but the nitrate level is not alarming. Just means there was alot of nutrient processed via die off. Keep in mind that the end process of the nitrogen cycle is the convertion of nitrates to nitrogen. This can take many months to even show signs of natural decline. Proper denitrification to the point where nitrates register zero without the use of dilution can sometimes take upwards of a year for some set ups.

Once ammonia and nitrite are undetectable without water changes to help it along, the tank is cycled. Once that's acheived, do a 50% water change to reduce the nitrate level. With the level you have (or may not), I would suggest a few water changes. This will also bring chemistry back into balance as it is often greatly skewed throughout the cycle process. Especially alkalinity and pH.

Cheers
Steve

 

[Slickdonkey]

Thanks guys; I wouldn't call this bad news at all, just good information! I'll try a 50% water change once nitrite is completely undetectable and will keep an eye on the levels following that.

In the meantime I'll try another kit to verify the high levels (using Salifert now).