Toilets running/clogged, showers not draining... Help!

Hi, and thank you in advance for any assistance or advice you may have to offer. I also want to preface this post by letting you know that I know absolutely nothing about plumbing.

I recently moved in to a condo that I purchased and in the past week I've had a slew of plumbing issues.

- toilet 1 never stopped running after flushing so I turned off the valve and waited, turned it back on and now it's working normally
- toilet 2 was stopped up for no apparent reason
- showered today while simultaneously doing a load of laundry in the washer and the drain backed up, then I noticed that the other shower had standing water in it and water had not been running in that unit
- tried to use a plunger on both showers and the drain sounded(?) clear, but I did get out some hair and debris... Showers eventually drained on their own, but I don't know how to go about fixing the problem or what the problem even is
- also, when using the plunger on the shower drain I noticed water coming out of the round metal fixture directly below the faucet, which I thought was strange... Posting link to video

https://goo.gl/photos/DsHroLhWyaAWfS1g8

Again, thank you in advance for any assistance you are able to offer. I would really like to avoid a high charge from a plumber, so any advice for work I can do myself would be greatly appreciated.

that is an overflow on your sink.

you have a partial clog in your main line, if it is your condo, you need to call a drain cleaning co,

if you have an condo association, call them

all depends on who owns what, consult your contract.


side note..if the drain system is yours to maintain, and you bought the place with out having your mechanical systems inspected by a third party, then you are a......................person that is fixing to learn a very expensive lesson

It is also possible the previous tenants may have sabotaged your drain lines?