Flter media #2 (restated more concisely)

I am concerned about my nitrate levels. I believe I practice good tank
maintenace. My fish levels are not low, but I don't believe they are
excessive. I don't have the plants, extra lights or knowledge to have had
much success with plants. Can anyone offer some inexpensive suggestions for
that. OR, can anyone tell me if relatively inexpensive filter additives such
as: ammo lock - zeolite - nitrazorb - purigen, etc. will help to any
significance and not be detrimental in other ways.
Thanxx
Bill