Help please!

[Smokidean]

Then was that 70% the first in a long time?
@Ch4rlie has gone over OTS above.

No... i do at least that much every week. The nitrates are always high. If I get them good.. within 3 to 4 days it's at death level again. I think I'm going to wait for the last fish to die then clean the whole tank and start over. I give.

 

[kwi]

Just the nitrates?
There must be something in the tank leaching into the water.
What are the numbers on your tap water?

 

[Smokidean]

Just the nitrates?
There must be something in the tank leaching into the water.
What are the numbers on your tap water?

Nitrate 0ppm
Nitrite 0ppm
Ph 7.2
Ammonia 0ppm

 

[Ch4rlie]

What test kit are you using by the way?

Just to confirm, tap water pH at 7.2
And tank water pH at 6

Is that correct?

If that’s correct then having pH at 6 is dangerously low for bacteria, this is another sign of OTS, pH crash.

Or at least you have stuff in your tank that may naturally lowers pH such as lots of bogwood, catappa leaves and certain rocks/stones?

 

[Colin_T]

Do you gravel clean the substrate when you do a water change?

When was the last time you cleaned the filter?

Have you lifted the ornaments and gravel cleaned under them and to make sure there isn't any dead fish or rotting food under them?

Maybe take a sample of your tank water to the local pet shop and get them to test it. Take your test kit too and test the same sample at the same time. This will ensure the test kit is reading correctly and hasn't gone off.