What The Heck Is This?

[mikenas102]

CO2 Reactor
This thing looks like a bunch of junk to me. Seems to good to be true. If it were that easy everybody would have one.

 

[ladrian]

Looks expensive?

In the UK they sell for £89.99 and the replacement blocks @ £17.50.

I have had good reports on them, but do not use one.
I understand you do need to keep an eye on the PH values.