i have began dosing 2 part(ALK and CAL)...

but i was just thinking of something...i am running chemi pure and purgien in my media rack...am i kinda defeating the purpose? will those 2 remove the 2 part?

thanks!
belle

They won't remove 2 part don't worry.

large amounts of gfo ( phosphate "remover") will drop your alk according to some sources.

ok cool!! thanks guys!!

The reason for this is because Phosphate inhibits corals ability to consume Alk. Once the phosphate is removed the corals can consume the Alk faster. The phosphate remove is not dropping the Alk.

That may be the case to some extent, but it is largely due to the rapid increase in localized pH around the GFO granules. This causes any soluble calcium and alkalinity to drop out of solution. This can drop the pH system-wide over time, hence the opposite effect folks seem to note. The reason you won't notice as much calcium gone is because it would have to drop over 2.8 dKH to even notice a drop in calcium, since most test kits seem to have a +/- 20 ppm accuracy.

you're fine.

If the there was such a rise in pH to cause the calcium and alkalinity to drop out of solution wouldn't you have precipitation? As far as I can tell the OP isn't reporting this...

You do, but most of it is actually localize (edit: localized[d]--oops) in the interstitial areas in and around the granules. The pH increase is not system-wide.

Bull

You don't have to believe me if you don't want to. There is plenty of information available on the chemistry of GFO that supports all of this. I apologize if I've come across brusquely or otherwise, since that was never what I intended. If I have not, then I don't appreciate the comment at all.

Alright good opinions, when calcium and alk make precip it is not snow day like most think the stuff bonds to pumps filters and for some reason doesn't skim out. Most people don't worry about running high levels of ALK and Calc because there is no need. I run my levels high and unless mag is way up there you will see the type of precip I'm referring to. Alk is much more delicate than calcium and resin filters really are bandaids on bulletholes. The idea that your tank can't sustain itself without the constant addition of these resins is rediculous. Get a turf scrubber or a chaeto fuge.