VHO issues and Kalk Question

[BCOrchidGuy]

I remember a year or so ago alot of talk going on about VHO end caps melting down and catching fire etc. Anyone had any trouble since? Was it a name brand that this was happening to or was it any VHO???

Is it possible to overdose Kalk, IE small demand+ Kalk mix in fresh water top off. Is there a point where it's safer to add additives rather than drip Kalk or go to a CO2 Reactor.

Doug