Green slimer, purple or orange digitata, purple stylophora , all are relatively easy to grow. Ora tricolor valida is good as well. There are few tenius that are fairly hardy
Neptune uses 2 wire sensor for temperature. I dont know if you can wire up anything other than those.. but its relatively easy to hookup a pt-100 or ds18b20 sensor and get ambient temperature readings, if neptune allows publishing external data using API, you can combine those two to get ambient...
Interesting, in my pico they are far less slow grower compared to mohawk or radio active dragon eyes. Even the grandis is lot fast grower than the sunny d. May be this has something to do with how old they are in the tank...
Mohawks, radio active dragon eyes, Green Bay packers, green lantern all will grow faster than sunny d. La laker, grandis , bam bam etc will grow at same or almost similar speed .