Can someone with more experience look at these results and tell me what the best course of action is? I did a 50% water change this morning and re-tested and the results were the same. I've not done a 100% water change since I started the tank, which was last September. I am planning to clean the canister filter tonight (Marineland 360). I have a 40 gallon tank with water that is about 5 inches deep. I know the nitrates are really high. I use tap water which when tested by itself, has no chlorine and is very hard. Alkalinity is also high on the tap water test.
This is the test strip after the water change
The chart for reading it is attached.
This is the test strip after the water change
![+V91x4zkS26e3biDU8dtIg.jpg +V91x4zkS26e3biDU8dtIg.jpg](https://data.www.tortoiseforum.org/attachments/222/222013-518f6c319e0326b885bf8ffa53519e40.jpg)
The chart for reading it is attached.