That's what people used years ago when plug in timers were not available. My mates marine tank in late 80's used multiple hot water/central heating timers to turn things on and off. Also used a modified central heating pump as main circulation pump.
Have seen both the posh aquarium PLCs and the Grundfos conversions.
I could see no reason not to use one of the timers. Cheap (second hand) and they have to be better build quality than most timer plugs.
I can't find the PC723 on Arlec's uk website.
Interestingly their digital 7 day timers look to have exactly the same display and button format as other makes I've used and which have failed. It makes me think they're probably knocked out if the same factory at minimal cost.
I've good experience with the Kasa smart plugs; you can add lots of different on/off points, don't rely on wi-fi, can control them remotely if you choose, don't lose memory with a power cut - oh and of course you can control them with a smart device if you really needed to!
Yes a Kasa is a great choice. They just added scenes. Which allows you to set up a group of outlets to turn off together.
I have set up two currently for equipment I want to turn off and on during a water change.
Biggest issue is:
- They are not 100% quiet, you can hear the motor slowly whirring away. Probably insignificant compared to filters, powerhead noise.
- Not accurate, +- 5-10minutes accuracy. Probably doesn't matter for fish, but when you have been used to digital accuracy of seconds, just a bit worrying that things haven't turned on/off at required time.
My best ever, still working 20 years later is a Timeguard timer. Unlike B&Q cheapy timers that use non rechargeable coin cells to maintain time and settings over power off, that always appear to self discharge and have a flat battery, so the timer loses settings on power glitch, these Timeguard ones use a rechargeable battery. Not cheap, but I suspect you are paying for quality. Now resigned to switching on and off Xmas lights. https://www.tlc-direct.co.uk/Products/SMETU17.html