Bio balls help

[RaeRae]

Are all bio balls created equal? I have a 32 gallon and have never run them. How many and what type? Seems the market is full of all types

 

[laverda]

Bio balls are not the best option for a reef tank. They are primarily used in fish only systems. Live rock is a much better choice for a reef system or a combination of live rock, skimmer and refugium or ATS. If someone is advising you to go with bio balls for a reef I would find a different source of advice.
If you going with a fish only system then bio balls with the most surface area are best.