I haven't tested or won't be running a controller I think but given it's down in the basement and pretty sealed off, I know the pH won't be great so it does need a boosting. Might stick the pH probe in tonight and see what it's like!
The controller is a great idea but I'm a simple man and that's beyond me haha
Not dosing anything at the moment, not enough coral to warrant it yet

When I do it will be via calcium reactor so increasing pH will be more important. I might do some testing to find out but I'd say it will balance out nicely.
Happy to help

haha
My tank is in the unfinished side of our basement.
What I discovered was that when work got the busiest for me, (inevitably right around the holidays) equipment would fail and it would happen when I wouldnt be able to get to the tank for a few days, and I didnt know it had failed.
Having a controller that would notify me when a piece of equipment failed would have saved me alot of money, and time in the past. Because of that, I will be buying a controller in the next 18 months or so.
It's less about wanting to geek out on the techie side of things for me. There are people who enjoy that side of the hobby, and I dont begrudge them that at all. For me it's more the ability to figure out something's going wrong and shutting it down and replacing it before things get to a catastrophic tipping point for me.
My wife is awesome and is supportive of me being in this hobby, but doesnt know (or want to know if I'm being honest) all the intricate details of what makes things tick. She's happy looking it briefly and knowing that it makes me happy.
If Georgia is more into the hobby than my wife is, and is able to let you know something's wrong and how to intervene, then you're good to go. If not, you might really consider some form of controller, even a rudimentary one.
No, they arent cheap. Like anything else in this hobby, it will take you down yet another rabbit hole of money and hours spent on the internet researching, asking questions and trying to learn more. However, when you look at what you've already got invested in your tank in terms of money and time, it's a drop in the bucket, and it will help you succeed and survive the inevitable equipment failures without missing a beat (or more importantly), losing anything.
Obviously, being in Aus makes it more difficult for you as I'm not aware of any Aus made controllers. Doesnt mean they dont exist, just that I'm not aware of them. As beautiful as your country is, and as much as I've traveled, I havent been as of yet.
I would look at what controllers have the best support in Aus and lean heavily towards them.
Just my thoughts, and worth exactly what you paid for them.
Thanks for the input on the Earmuff...my 40 breeder is too small for one, but there are other I might be able to get away with now that I know the door isnt completely shut on keeping sandbed wrasses.