someone school me on some ph knowledge

im pretty sure my seedlings have a fucked up ph right now the stems are purple and not showing too much growth. they were planted 2 3 days ago and I'm going to get a ph reader as well. How can i test the ph of my soil if i have my seedlings in disposable cups that dont really drain but just soak up the moisture.

any ideas?

oops,

planted 3 days ago

i'd be patient, did you say you planted seedling 3 days ago, so i'll assume they were all germinated and whatnot. I think the purple stem is normal for seedlings(i'm a cloner) 3 days isn't much time. How close is your light?what type of light?

but ya def check your ph thats a good thing to know, be more of a problem later

i have 2 100 watt cfls aimed with focused light fixures about an inch away and ive been watering from the bottom with tap water for the first 2 days but yesterday switched over to stream water.

still wondering how to go about testing the ph of my soil if my pots dont drain...