Yes it all depends on the livestock and all. Normally you want to do a 10% change a week.
How long has the tank been set up?
What water changes where you doing before?
Nitrate is the end product of the nitrifying bacteria cycle of breaking down waste.
You want to slowly remove the nitrate level in the water over a several steps. Rapid reduction of nitrates can be just as harmful.
What you want to do is install cheato filter or denitrification tower to remove the problem other wise it will come right back