What Alkalinity (kh) Is Best For Reef Tank?

[sahmof2]

Our current alkalinity is between 200 and 300 ppm. According to our 5 in 1 test strip, ideal level is between 180 and 300 ppm. Today someone told me, that had a well established reef tank, that alkalinity should be low. We have had our 55 gallon tank stocked for over a month and have noticed little if any change in the small amount of coralline algae. We are keeping the calcium level between 350 and 400. I add every few days a dose of liquid gold plus by corallife. I have around 110 lbs of live rock stacked along the back. If alkalinity does not matter, how can I accelerate the coralline growth? I have zoanthids that are doing great and growing and my mushrooms are doing good but not yet spreading. My pH is around 8.4 and nitrates/nitrites and almost undetectable. I currently have not yet tested phosphate level. Any information would be appreciated.

Thanks

 

[andywg]

For good stony coral growth you want pH around 8.2-8.4, calcium between 400 and 500ppm and KH of around 10-12 German degrees (about 170 to 215 ppm). Some people keep the alkalinity higher, though others report some problems.

Phosphates will very quickly inhibit coral growth, so check on them.

If you haven't already, check out this FAQ thread by Randy Holmes-Farley. It will teach you everything you wanted to know about reef water chemistry (and more).