Do I really need to buy?

[Ginu]

I honestly think it depends on husbandry and time invested...

In Alberta I would strongly suggest using RO/DI water as the water is not the greatest over there... In Vancouver the water is actually quite good although you never know when the city cleans the water and with what.

Ato - is it necessary? Not really but then that adds to the husbandry of the tank (manual topoffs). For example, I hated doing water changes so I added a Apex DoS pump and it automatically changes 10g of water per week..

Apex - is it necessary? not really but then you need to manually monitor turn on/off when needed. BRS has a really good vid on controllers and why you want one; watch it and if any of it is relevant to what you need, then you need a controller of some sort. I killed all the fish in a tank due to a heater failure before, so a controller became mandatory after that...

Do you need media reactors? - depends on how you plan on removing Nitrates/Phosphates

Do you need a dosing pump - not really but then be prepared to dose Alk/CA every day to keep the parameters up all depending on what you stock in the tank and the growth of coraline algae... Also its not recommended dosing Alk buffers all at once as it can cause major swings and precipitation... for example my system is 6 months old now and I dose 82ml of Alk and Ca solution every day... I'd be killing the tank if i dosed 80ml of soda ash all at once...