how much calcium is absorbed by deposits in pipes etc?

[upsetter]

In trying to raise my calcium, I just wondered if the calcium deposits in our pipes, in overflows, on walls near surface, ... absorbed very much calcium from the water. I have quite a bit precipitated onto my overflow walls & wondered if I needed to scrape it all off on my next water change? I've always left it alone because I like the little tubeworms that grow on it.

[Randy Holmes-Farley]

Yes, if you are getting significant deposits on heaters, pumps, etc, then that can be a significant sink for calcium and alkalinity.

They ways to reduce that are to keep the pH from getting too high, and the magnesium from getting too low.

Also, the higher you push calcium and alkalinity, the more likely such precipitation is. Scraping it of is not that likely to be useful in preventing more precipitation.

[upsetter]

Thanks Randy. I dose kalk at night, but ph is never over 8.2. I have had low magnesium levels in the past though(900-1000) & used to get quite a bit of precipitation. I've never had a problem with high calcium or alk levels, usually the opposite if anything. I just bought my first reactor a couple weeks ago and am still tuning it, but I think things are headed in the right direction. Salifert recommends mag levels of 1300-1500 depending on salinity. Should I be shooting for this level? I've also heard as long as mag is about 3x your calcium level you're balanced and o.k.?? Which is the case? I thought precipitation on pumps & heaters was related to the heat. Are you saying correct magnesium levels will reduce this? I guess that's exactly what you said isn't it :)

[wtrhed]

Having the same precipitation problems after adding my reactor. Tagging along. And yes it will definately collect on everything. I had to open up my skimmer pump, only to find the impeller shaft and housing FULLY encrusted. I have never dealt with this problem before. Would love to hear what Randy has to say.

[Randy Holmes-Farley]

Should I be shooting for this level?

I'd aim for about 1300 ppm Mg++. :)

This article will give further details:

Magnesium in Reef Aquaria
http://www.advancedaquarist.com/issues/oct2003/chem.htm

I've also heard as long as mag is about 3x your calcium level you're balanced and o.k.??

No, I don't agree. The optimal magnesium level is not, IMO, related to the actual calcium level. I can't see any reason to think that desirable, except in the rough sense that the NSW level of Mg++ is roughly 3x the NSW level of calcium. But if calcium is low, should magnesium be low? I don't see why.

wtrhed:
Have you measured magnesium?

[upsetter]

Thanks Randy!! Great article too. Another small piece to the ginormous reef hobby puzzle. Could you mention which of the salts had higher mag levels. I couldn't get the links to work in the article where they were mentioned.

[Randy Holmes-Farley]

The tests are a few years old now, but here's a working link:

The Composition Of Several Synthetic Seawater Mixes
http://web.archive.org/web/20030608135355/http://www.animalnetwork.com/fish2/aqfm/1999/mar/features/1/default.asp