Painful lumps in armpits after first use of brand new hot tub

[megan123]

Hello, I just recently got a brand new X7 Bullfrog hot tub that I set up using the 3 step Bromine method. HOWEVER, I believe I really messed up after watching some YouTube videos where it said that you don't need to shock your hot tub prior to first time use since it is fresh water. So, I got all my chemicals balanced: pH, TA, Calcium Harness, and I added a reserve of Sodium Bromide and put a floater of Bromine tablets in. The water sat for a day at about 36 degrees F while the electrician finished setting everything up and then sat another 12 hours or so once heated up to 103 F.

I rechecked that all the chemicals were good and myself and 3 friends were in it for about an hour and a half and as soon as we got out, I then shocked it with 8oz of bleach.

A few days after using the hot tub, myself and 3 friends have ALL developed painful ~coffee bean sized lumps in our armpits. They are not red but are painful to the touch under the skin. I'm worried that there may have been some kind of bacteria in the pipes and that I really messed up by not shocking it prior to first use. Has anyone ever had something like this happen? One of my friends has started a course of antibiotics for it and hasn't noticed much of a change so far but I guess we'll wait and see..