How to control PH at night ?

[Casey8]

I am putting a very long hose to connected to my skimmer valve and go straight to my small air vent in my bedroom 24hrs. I am also planning to put a big blanket to cover up my small refugium so the light is left on the whole night to control the PH swing. I really don't like the way it has changed too much from 8.3 down to 7.5 in the early morning.
Thanks for your inputs, guys. I hope I can find the solution to deal with this problem.

[Aquarium_Medics]

Be careful when covering your tank, you can actually increase the Co2 levels as the cover inhibits the exchange of gases.

[Casey8]

Thanks for reminding me. I will try tonight and test it again tomorrow let see what happens. If it is not working I will just have to live with it as reefwars and everyone else has told me just to leave it alone.