What do scrubber users need to dose if they stop water changes????

[duganderson]

I've read about a few folks that stop doing water changes (or do them 1 time per year) when they start running a scrubber in coral and fish tanks.

I'm assuming those folks need to dose multiple things like Calcium, Alk., etc.; however, I'm curious what these folks actually need to dose????

[SantaMonica]

Cal, alk, mag, maybe str.

If you don't feed nori, then dose iron and iodine.

[Floyd R Turbo]

Much evidence is also pointing to the need to dose Potassium. All the tanks I run scrubbers on have low potassium. All the tanks that I have tested that do not have scrubbers on them have proper potassium levels.

One of my original scrubber customers was dosing K (potassium) like mad, then he took the scrubber off to let the tank "get dirty" and his K stabilized. he put the scrubber back on and it started dropping again. So IMO the jury is in on this one. Test and dose K. In that order.