Biological (bacterial) Additives

Can a biological (bacterial) additive, like Stress Zyme, (help) to start the cycle?

 

IME , Yes , products like that and Hagens Cycle and Brightwellls MB7 and Dr Tims , one and only, bacteria in a bottle can certainly help to mature a tank

they can also be very useful in the event of tank issues, power out, some part of the system not functioning etc , and having products like that on hand can be beneficial should you need to reboot a set up or transfer inhabitants to another 1

are they strictly required for a cycle , well no not really
nature will provide all that is required, even in our closed systems in terms of bacterias required to cycle a fish tank
all you need is a source of nutrients to kick start the culture ( many use table shrimp or strips of fish for this purpose)

 

Stress zyme to start a cycle, no. Stress Zyme contains bacteria to break down ammonia and nitrite. It says that directly on the bottle. I would use that product once your system is established and you are having a problem with ammonia or nitrites. I would go with one of the products that Steve recommended. Those will work.