Energy is cheap where you live... over here it's 12c in the first tier, and goes up to 24c after that.
Absolutely. We moved from Alameda, CA. We didn't have air conditioning there and lived in a 950 sqft 2bd/1bath apartment. Now we have central air, 2400 sqft, and our electric bill is less(only by a few bucks).
Don't know about the plumbing... I tend to keep things as simple as possible, and when you connect that many things, they might start to work against each other. But I am not that knowledgeable with that sort of things.
I left a job with big oil to move to Atlanta, so I kind of miss the plumbing and wanted to have some fun with it.
Your controller setup looks good. Over here, the DIG controller is still sold for $33 at the HD. Keep in mind one limitation of the WC
-- you can only have two things "on" at the same time.
Yeah, absolute bummer on the DIG Controller. I tried to get one through HD's website, but they don't have it(or at least didn't) on the website. I should have had a buddy buy one for me and mail it, would've saved me $30.
So far, I only need to have 2 relays on at one time, but that includes a light/co2 piggy back. I may have to pull the co2 off and put it on an outlet timer(I see that you ended up having to do that too).
I found that with light and pumps adding some heat to the water I don't need heaters at all... Might be different for a Discus tank though.
In the summer that will probably be the case for me, but right now, being winter, our basement drops down around 60. It's only a semi-finished basement. Before the end of the year I'm giving it its own HVAC zone, but I'll still probably keep it in the mid 60s.