Hello, long time lurker but just started my first reef tank a week ago. I’ve been in the freshwater hobby for over 5 years and just recently made the jump I’ve been dreaming of.
I am asking this question for a few reasons:
1. I’ve seen different threads on here with very different opinions. There is a post from 2019 where many people bring up the temperature swings that occur in the wild throughout the day and even how that can condition corals and they will be fine. Then there are other posts in here where numerous people preach a very high level of stability as the major key to success.
2. The tank is a pico around 4 gallons, I’ve been monitoring it all week and so far the temperature seems to swing about 4 degrees maximum throughout the day, with the lid on it’s been 78-74 and 72-76 with the lid off. I’ve been topping up with little bits of fresh water every other day to keep the salinity more stable.
3. The most common fish killer I’ve experienced in freshwater for me was overheating. I’m pretty traumatized by the idea of coming home and seeing the tank at 92 degrees by this point. I’ve seen 3 heaters go out this way, would hate to experience it again.
4. I plan on using pretty hardy corals. RFA’s, Xenia, GSP, mushrooms and maybe some leathers. Going with big water changes weekly.
Looking for opinions, thanks!
I am asking this question for a few reasons:
1. I’ve seen different threads on here with very different opinions. There is a post from 2019 where many people bring up the temperature swings that occur in the wild throughout the day and even how that can condition corals and they will be fine. Then there are other posts in here where numerous people preach a very high level of stability as the major key to success.
2. The tank is a pico around 4 gallons, I’ve been monitoring it all week and so far the temperature seems to swing about 4 degrees maximum throughout the day, with the lid on it’s been 78-74 and 72-76 with the lid off. I’ve been topping up with little bits of fresh water every other day to keep the salinity more stable.
3. The most common fish killer I’ve experienced in freshwater for me was overheating. I’m pretty traumatized by the idea of coming home and seeing the tank at 92 degrees by this point. I’ve seen 3 heaters go out this way, would hate to experience it again.
4. I plan on using pretty hardy corals. RFA’s, Xenia, GSP, mushrooms and maybe some leathers. Going with big water changes weekly.
Looking for opinions, thanks!

