Need more nutrient

[TankMaid]

All, I have a 55g lowboy with a trigger 36 sump. My cheato is keeping my nitrate and phosphate at 0. I would really like to add some fish but I’m not sure what I can add. I have been feeding as much as the fish are willing to eat. They are all fat and happy. What do you think I should add?
Current stock list:
Clown
Blue eye Kole tang
YWG
3 black mollies
Piston shrimp
Cleaner shrimp
~5 hermits

 

[Idoc]

If you need more nutrients in the system, remove a portion of your chaeto until you achieve the nutrient levels you want to maintain, then keep the chaeto growth at that level.

 

[TankMaid]

I rather do it with fish if at all possible