Air Purifiers

How do i know when i should replace my air filter?
How dark should it be
I’m talking about the air filter in my Truck ( not house ) lol

My whole family has been sick for about close to three weeks now with bronchitis.I have cleaned when my energy has allowed me to (which isn’t much).I want us to get better.We are all on antibiotics and I use a humidifier,hand sanitizer to help apart from the constant hand washing,covering of mouths and tissues used.Today I decided to focus my enegry on my childrens room.I cleaned their room from top to bottom,stripped their bed clean,vacuumed and dusted off whatever I could dust off.Then I went back and blasted everything with lysol. Even the walls.I let it sit for a little bit and then I opened the window to air it out.My question is,do you think I did it right?What else could I do to get rid of the bacteria in the air?I’ve changed the heater filter and cleaned the vents the best I can.Unfortunately this house is the dustiest house I have ever lived in!Anybody have any ideas as to how I can beat the bug?
capricorn lol girl. we have been so sick i wouldn’t wish it on my worst enemy!

I could be completely clueless, so hear me out lol. yesterday i smoked marijuana for my third time and i right before i went to sleep my hands were really itchy, like really bad between my fingers but mostly on the tops of my hands. I was wondering if this had to do with marijuana? I have alotttt of allergies.. food, detergents, air born irritants, you name it. However, at my workplace.. there’s sanitizer in the water that i wash my hands with (i’ve been working there for a while and it usually causes my knuckles to get red but nothing like this!) so I thought this was what caused it. (ps: i haven’t worked in about 2 or 3 days) So today I went to a pharmacist and he gave me some cream that relieved the redness and itching for about an 2 hours but it keeps coming back.. now my feet are broken out so i guess that rules out the water at work? theres been no real changes in my diet or detergents or anything and i don’t recall this happening the last time i did marijuana. so any suggestions? excuse my poor grammar as well, im in no mood to be proper lol