Do I really need to buy?

[Wheelman76]

I can see smaller more frequent water changes being better as far as replenishing elements and keeping the tank a little more stable. When it comes to reducing nitrates though larger water changes are obviously better as you are removing more at once , as opposed to smaller more frequent water changes where you keep replacing some of the new water that was just changed. Simple math and I'm pretty sure this topic has been beaten to death on here many times lol.