Woah! You've got me excited about new Tentacle board possibilities!Yes, they are a bit noisy.... They have released a new, larger pump called, PMP-L . I haven't tried it as I'm fine with the three that I have.
I've been testing out a new MarkII Tentacle-T3... White Box Labs sent it to me to evaluate for them. It supports the EZO-FLO stamp with a small 3 screw terminal for attaching flow meters. They also have a nice 'aux' Connector that allows you to extend the i2c bus beyond the board. Looks good. This is a prototype, so it will be interesting to see how it looks in it's production format. They've got a few more underdevelopment... They showed me schematics of a new one for the Pi-ZERO-W... I like that one... They also spilled word of a Tentacle-T8 (but didn't have anything to show me)..
Atlas-Sci is also selling a little 'bus expander of sorts'.. or 'i2c hub of sorts' called the Sensor bridge... Really useful for the 5 pin devices (like EZO-PMPs, EZO-HUM) devices.... as you just make one home run back to the RaspberryPi or Tentacle board.
So yeah, I'm definitely bought into the atlas-sci and ncd-io 'ecosystem'.. LOL.
Surprised you felt like you had to go all the way to 8GB.. My flows are super complex (albiet not as much trending as you are doing), and I'm finding my 4B w/ 4GB to be sufficient for now. I'm going to work with InfluxDB, Grafana and MQTT on this Raspberry Pi in conjunction with NodeRED.... but alas, I need to finish up this refactoring I'm doing now.
Funny enough, I built a Node-Red node over the weekend to facilitate communication to these devices. I'll publish it this week once I work out a few lingering issues. It'll handle both default and custom I2C addresses, store temp compensation in context, and support all current commands published by Atlas Scientific. Output is also grouped by command, status, and values.