water smell/nitrate spike

[VulcanNinja]

Lately I have noticed a slight change in my tank's smell. It still smells like an aquarium, but has a slightly more metallic smell. I guess metallic is the only word I can come up with.

I just did a test and my nitrate is through the roof. Why is this happening? I think it may be cycling, as I added a completely new filter but tried to auto cycle it by using old gravel. Nitrate is 80 or higher.

 

[PeterM]

Thats far too high to be comfortable for your fish. Nitrate is tolerated far more by fish than Nitrite, but a level of 80 is going to cause some problems indeed.

The best thing you can do is take out all of the ornaments, wood and rocks from the tank, clean them in tap water and let them dry. While theyre drying you should do a full substrate clean. I have bad experience of pools of uneaten food and decaying plant matter getting trapped and I had no clue they were there. It led to a similar situation that youre facing now, although there was no "metallic" smell... just a more "theres something in here that doesnt get out to go to the bathroom" type smell.

Also, if you can, test your water for iron and phosphates. Tap water around the world has highly varying levels of these, and any present in a tank will build up over time - water evaporates so you top it up, unintentionally increasing the concentration each time you do.

The reason for this is probably indeed a cycle or mini-cycle. The best thing you can do is add a mature filter to the tank along side your new filter, and keep on top of the nitrate levels with daily water changes. If I were you, Id do a 30% to 50% water change right away just to get that Nitrate reading down... thats a very uncomfortable reading.