Ok, I've had my top off running for a little bit, absolutely love it simply because I don't have to freaking top off the water all the time! Now I just need to clean up some cords.
Some observations/comments for others who might want to do this and are scared like me
I got my switches from Aquahub.com they were a bit cheaper than autotopoff.com, there was a little bit of assembly but if you can't do that level of assembly you probably shouldn't be doing DIY projects in the first place
. Plus they sold a' la carte, so I ordered a couple additional pieces.
Hooking it up to a controller/timer is key, you do not want to top off water every time it dips below a level simply because you don't want your pump turning off and on multiple times per day (very easy way to prematurely ruin a pump!)
For my 180g tank I use a maxijet to move the water, set it up so once a day for 1 minute (smaller time period I can do) it turns the socket on, and if water is low (which it should be) pump moves water. Only 1 minute is needed because it MOVES water, in fact if I could do 15 seconds a day I probably would!
Other tank is with one of the Tom's aqualifters, figured an energy efficient pump would be nice... stupid me ran the numbers and found how energy inefficient those pumps actually are, sure they don't use much energy,but they don't move much water either. Anyways, I had to setup a second reservoir for this because when my water reservoir is completely full its higher than the sump, so there's a slight siphon effect that occurs, its slow, and I wish the aqualifter had some "shut off" mechanism that doesn't allow water to move, but it was an easy enough fix. The timer for this one is on for ~30 minutes a day, which is more than enough considering how much evaporation occurs, but I leave some wiggle room just in case. Downside of the aqualifters is their head height is quite low, which is why I couldn't use them on my other tank because the sump is not on the floor.
Not quite sure I want to float switch my reservoir, I think if anything me manually having to fill it makes sure I do double check everything periodically.
Would I use peristaltic pumps? Probably not, they're quite pricey compared to the alternative, and really you don't need to add water that slowly to a tank. What I would like to do is have everything outside via 1 pump and pvc piping to the tanks, with some PVC solenoids to open when tanks need water, however PVC only solenoids I could find were all in the $300 range, I don't think it's worth that much flash either.