I run GFO, I change it out every 3 months or whenever I remember. I test (deltec) every month or so but I don't base my GFO changeout on the reading (its usually always the same or "acceptable). However lately I've had higher PO4 readings so I've been a bit quicker to change out my GFO. I also have been doing larger waterchanges lately so that may contribute to lower PO4 levels.
__________________
Christy's Reef Blog
My 180 Build
Every electronic component is shipped with smoke stored deep inside.... only a real genius can find a way to set it free.
|