water parameters
 

Is there anything in these water parameters that could explain,old coraline algae is fine but not growing,and the new coraline that started to grow here and there has dissapeared over about 2 weeks?
S.G 1.024, alk. 9.8 dkh, calcium 370ppm, magnesium 1150ppm, PH 8.3, phosphates 0, nitrates 0, temp.78F.

looks like your calcium and magnesium levels are low??

They are a tad low, and may have some contribution. The phosphate may also not be as low as you think. It is a big coralline stunter. What kit did you use?

How would you describe your skimmer? Highly effective? Elevated organics can also stunt coralline and other calcifying organisms.

These articles may help:


Solving Calcium and Alkalinity Problems
[url]http://www.advancedaquarist.com/issues/nov2002/chem.htm[/url]


Phosphorus: Algae’s Best Friend
[url]http://www.advancedaquarist.com/issues/sept2002/chem.htm[/url]

Magnesium
[url]http://www.advancedaquarist.com/issues/oct2003/chem.htm[/url]

My phosphates are either 0 or very close to it,the lab where I work tested it and it tested at .004ppm my kit is a cheap one by aquariumpharma. but gave me zero as well.I love my skimmer its an old fashioned counter current hang-on skimmer,the air to water area is 3 1/2"x 22" the flow is low to give good contact time,it takes out about 1 1/2 cup of green/brown liquid every 2 days.

Need to make a correction on my previous reply,my phosphate test at the lab showed .04 and not .004,but I believe that this is acceptable.Thanks for the input.

Well, 0.04 is acceptable, but is not especially low. It is still above NSW levels. I aim for slightly lower, myself.

The reason that I ask about skimming is that organics can reduce calcification. Reducing organics more may help more.

Do you have hard corals, such as SPS, that grow rapidly?

No ,all I have is live rock /base rock some zoanthids and yellow polyps.What I want to do right now is perfect the water parameters so that I can keep more delicate coral,my feeling is that if the coraline is'nt growing the coral probably won't either.

Yes, that could well be true. I mostly wanted to see if it was something specific to coralline, but it may be something that inhibits calcification in general, and in that case, the culprits ar usually phosphate (organic or inorganic), other organics, low alkalinity, low calcium, low pH, or some combination of all of those.

I'd boost the calcium and magnesium, but that may not solve the problem. Let us know what happens. :)