Uh oh, danger in my 30 gallon

MXS

Hey everyone, I just used one of the 6-way test strips for my freshwater 30 gallon. The tank has been set up for over a year.

It contains:
1 Plecoi
1 Chinese Algae Eater
2 Neon Tetras
1 Zebra Danio
4 Black Tetras
2 Orange-Finned Tetras
some small common pond snails

The readings I got when I compared it to the colors given to me were
Nitrate - Danger (Not really "danger" but it's high)
Nitrite - Danger
Hardness - Very hard (300)
Chlorine - 0
Alkalinity - Ideal (120)
pH - Acidic

I recently had a lot of fish die, maybe 2 weeks ago, I have 3 live plants in the aquarium.
Did the dead fish cause the problems?
How can I solve all of these problems with my water?

DragonFish

Strips can be very inaccurate and are likely not giving you proper readings.....before you totally panic, go and have your water tested, making sure its tested with a liquid test kit and ask for specific numbers, or snag yourself a liquid test kit like the API brand(which I highly advise no matter what). And just to be safe, do a PWC....20% maybe. A PWC can never hurt.

aunt kymmie

+1. Get a liquid result reading and let's go from there.