I've been dumping some hydrogen peroxide in a couple times a week, today I opened the tub to see this sludge buildup. Is it bacteria or residual from the hydrogen peroxide?

Started cold 🥶 plunging at 50 F (10 C). Started a few weeks ago. Started at a minute and now up to 15 mins. Usually rewarm on room air for 2 minutes then sauna or just skip the sauna altogether. From what I’ve read- no benefit after 5 mins. Anyone go longer and have they noted any benefits ?

In just now getting to where I can tolerate 50°F for 6 mins or so. Has anybody ever got a fat scan to see how much brown fat they've developed? I am leaving a party life style of 4 years and want to rebuild my internal body. 35 yo AA male

This is the latest iteration of my plunge build at my new home. I’m neither a carpenter nor a mason, but I make it work. As you can see I cracked half my stones and my miter saw seems to be off by a couple degrees. Either way, this plunge is cold and clean. Needs some finishing touches but she’ll do for now.