Hello
I don’t print often, so I wonder what is the lifespan of the resin that is in the tank LT between 2 prints ,
If you keep the printer in dark place (away from direct sunlight, covered or placed in cabinet) you can use it without any problems after 2-3 months.
If the printer stays close to the windows (high level of UV light) it’s possible to get deterioration of the resin quality much sooner - the protective cover is not light sealed and also some part of the UV light can penetrate directly through the plastic and semi cure the resin.
Personally I keep the printer closed in a cabinet with weak constant air extraction (put 0.33uF / 650V capacitor in serial with the 125mm fan power supply).
Thank you Luben.
Me too I put the printer in a dedicated cabinet, so it is totally in dark.
After this 2 or 3 month how do you see that the resin is not ok? By print failure? By the texture?
If you see some film built on top surface or if you see some non homogeneous areas inside the resin in the tank it’s a sign that you need at least to filter the resin before trying anything. My expectation is that even after 5 months in idle state the resin will print correctly if there is no ambient light and the humidity & temperature are in range.
Personally if I see the resin to look smooth and even I just run another small print to see how the resin behaves. Printing even the smallest detail will mix the resin thoroughly in the tank (even wondering why they don’t put an option in firmware for auto mix the resin each few days if it’s idle).
Ok I notice it 
You talked about temperature, in summer it could be a bit hot in the dedicated cabinet for my printer, is-it a problem?