How do you know when Phosban and carbon is used up.

[PJsStuff]

How do i know when to change out my phosban? Also how do you know when the carbon is used up?

[smcdonn]

I am not sure about carbon but phosban seems to last me quite some time. I buy the small container of it from my LFS and change it out every 4-6 months or so. Now is that how long it will last you? I have no idea. All I know is that it knocked out my hair algae and keeps me free of it changing it on these intervals. Hope this helps a bit.

[BreadmanMike]

I never use carbon for more then a week, but that's just me.

If you're running phosban in a reactor it is good until you can no longer get a reading of zero phosphates on the effluent. If you're running it in a bag, I have no idea. :)