Leave the cover on or off ?

I have a unheated pool and wonder if I should leave cover on in the summer when we are away for a few days ?

Last time I left it for 3 weeks algae and all sorts grew in it.

You'll grow a lot less with it covered, than with it uncovered.

BUT . . . you need to make sure all algae is dead and that the chlorine has been high for a couple of days BEFORE you cover it. I can't offer much more advice that that; many of the chemicals we recommend here, are not readily available in the UK!

Thank you
The chlorine level is high so will see when we come back.

Have fun!