There are numerous causes for poor clarity, so isolating which specific cause has found you may help eliminate the problem. An incomplete list (below) might point you toward some things to check. You may not need fining agents if one of these is easily correctable. (Some of these are all-grain only.) For me, recycling the entire first runnings thru the grain bed did the trick.
Some grains (i.e., wheat & adjuncts) are inherently higher in protein & cellulose levels
Protein rests to break down same
Proper mash pH (5.2 to 5.5, usually)
Vorlauf recycling of first runnings
Proper sparge temps
Too-fast sparge can allow unfinished "starch bombs" to reach wort
Insufficient boil time
Insufficient boil vigor to coagulate proteins in a good hot break
Too-slow wort cooling to create a good cold break
Use an Irish moss/carrageen/whirlflock to aid in coagulation of proteins
Use more flocculent yeast
Keep in primary longer and/or use a secondary/conditioning phase to aid clarification