Horizon Ventures 2-Pack Pool/Spa Scum Eliminating Reusable Scum Ball

Can't complain, does what is says. Within a week of putting it in the hot tub it had a ring of green around it, which to me means it must be working! Cheapest I've seen too.

These seem to work. You can see the oil gathering on the sponge after it has been in your tub for a while. Given the price, I think they're worth buying. They certainly do no harm, and at least appear to be gathering up oil and grime that isn't being picked up elsewhere. I regard them as a weapon in my overall cleaning arsenal.

Second purchase of these for our hot tub, completely gets rid of scum and froth on surface, and lasts just under a month with constant use. Definitely will buy again.

delivered quickly not sure if they really work but I have used and not sure I will replace.

Cheaper than the scum bug but doesn't do as good of a job. I will just get the scum bug next time.

Cracking little things, although don't take any notice of the 'replace every 30 days' soak them in filter cleaner, rinse & scrunge, good as new. They do what they say!

Don't have scrum so presumably theory make a contribution to the cleanliness of the tub.

Previously had a floating sponge that did the trick but wore out after many washes. Bought these to do same job, but they have absolutely no effect. I still get a scum line and they collect nothing. Waste of money