Ozone questions
 

In process of making and setting of small ozone reactor(up to 50mg/h of ozone and tank is less than 100gals)
Is there any know size or recommendation for reaction chamber? My guess would be that for such relatively small ozone ammount it can be pretty compact? That is my goal, a unit compact as possible

Also, is there any recomnendation for safe filtering of ozone effluent?
I can put efluent to go trough a carbon reactor but i would rather that is stand alone unit with own carbon chamber and would be great i know how much of carbon is needed(or can be used something else instead of carbon?) and how often to change it. I search a lot but i can not find that answers

Thank you for link but still no clear answer about carbon (minimal) amount

If you do NOT smell the ozone there is enough carbon.
It has a distinctive odor so you will be able tell.
Take a SMALL WHIF so you know it.
I would use @ least a cupful to start & increase as needed.

In your opinion, is air filtering more or only important? So that we are sure that there is no o3 left because its bad for human healt? Or water need be filtered as well? Because even small dosage of o3 can make enough byproducts(bromates?) to be toxic for tank inhabitants?
There was reports from people who use o3 on skimmers with apparently no ill effects even without effluent filtering. Maybe that is no so important with small dosages, or carbon reactor elswhere in system is good enough, hmm

I have no knowledge on water filtering.
I only know that exposure to ozone is unhealthy for us humans & carbon is the filtering agent.