Hi all.. new to the forum.. I used to work with electronics back in the 80's.. was C&G 224 qualified but didn't stay in the profession so I've forgotten most of it!! I'm ok with a soldering iron.. but don't really want to get to involved in making circuit boards... breadboard maybe... So I'm hoping I can get a little (lot) of help from you guys! OK.. so here is my problem... My house is powered completely by solar.. I have quite an extensive system so we live pretty normally... but I'm trying to run a hot tub.. I have fitted a low wattage circulation motor (80w) so I can run that as long as I want.. but the heater is 1kw, so obviously I don't want that running all the time... So.. I have fitted a 7m long solar water heating panel to take over the heating, and that is doing an amazing job... But, I don't want the pump running at night because the black solar panel will remove the heat as quickly as it put it in during the day... So, what I need is a switch circuit using a photocell to detect daylight, ....that needs to be adjustable.. i.e I don't want the pump to start to run at sunrise, only when it receives direct sunlight and therefore the panels will be getting direct sunlight... For instance I don't want the pump to run on cloudy days (not that we get many)... get the picture? The circuit would also need an override so that I can run it at night if we use the tub, which is fine as the pipework for the solar has a control valve so I can run the motor without the water going through the panels.. Any help would be much appreciated..