Best plants for reducing nitrates

[Papagoomba]

So my tap water has between 30-40 ppm nitrate so doing water changes seems to be a waste at this point. My question is what would be a good grouping of plants that would help to reduce the nitrates and keep them in check? I currently have pogo octo in all of my tanks aswell as some val.

[Scapexghost]

Hornwort and water wisteria. These plants are used in sewage treatment facilities for this purpose. They will also remove heavy metals as well. Duck weed would probably be third, but most floating and stem plants would work well. I'm not a huge fan of hornwort, mainly b/c it doesn't root and when it struggles it will shed its needles. That said it could be a blessing for your situation. It's a candidate for fastest growing plant in the world.

[Papagoomba]

Awesome. Thanks. Ill look into those

[JettsPapa]

It's my understanding that most floating plants do a good job of removing nitrates because they have constant access to carbon dioxide.  Guppy grass may be another good option for you.