Has my tank lost its cycle?
Please let me know if I am missing any pertinent information or if this is the wrong forum to post this in.
I normally test my tanks every week before I do a water change.
Last week I tested the nitrates on my 55 gallon tank and the nitrates were 5 ppm. I didn't test for ammonia or nitrites because I figured I didn't have to on a cycled tank. I was testing the nitrates because I wanted to make sure the water quality was fine for the tetras that are new to our tank.
This morning I tested the water because I noticed something suspicious on one of the tetras and wanted to be able to give water parameters in the post.
I was so surprised to find 0 nitrates. It's possible that there are nitrates but the color was more yellow than orange so if there are nitrates,the amount is barely noticeable.
There are a few plants in the tank but I don't think it's enough to absorb the nitrates. Did I lose my cycle? I'm hoping I haven't so I'm thinking of not doing a water change this week.
ph - 7.4
55 gallon tank
Livestock: 20 neon tetras, 2 panda garra, 5 zebra danios
Plants: small anubia, large anubias, small/medium Java fern, 1 small Windelov Java fern, 1 medium Amazon sword (or maybe Argentine- can't remember)
Filtration - Marineland 350 Biowheel Filter (can't think of the exact name)
Random information: 10 neon tetras added 11/12/16
12 neon tetras added 11/19/16
1 neon tetra found dead 11/21/16
1 danio and 1 neon tetra found dead 11/23/16
I didn't test the water on those two days unfortunately. I wish I had though.
I will try to edit this post to upload a pic of my tank.
I will post a separate thread to figure out what's going on in my tank.
Thank you in advance.