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About Coralline...

Posted 02/15/2016 at 05:44 PM by Sk8r

About coralline: the purple FYI.
Coralline is a red algae that shows as purple: it binds calcium, and covers rock in a purple coat that many hobbyists find quite pretty. And it does limit where pest algae can grow. It seems to start out as a dark red velvety coat and then starts laying down the calcium-shelled purple/pink stuff right amid it.

Do you want coralline? here's how. First, obtain some live coralline. A single tiny spot on one rock will do. You can also buy it ground up in a bottle. But if you have a single spot on a rock that's all you need for a starter.

Second, set your parameters as follows: magnesium 1350; alkalinity 8.3; calcium 420. Dose in that order. Test between doses, because getting them there is gradual and you should wait 8 hours before testing: takes time to dissolve and all that. Dose the mg up all the way to 1350, (may take several days) then start raising the alk, THEN start raising the cal. I use Salifert tests, which give you numbers for those things, not colors.
Once you've got them there, keep them there with dosing. I use Kent Tech-M, Kent DKH Buffer, and Kent Turbo Calcium for the 3 doses. Whatever gets it to that reading. Your fish and corals will love it. If you have clams or stony coral that sucks up calcium like mad, you may consider adding lime powder (kalk) to your topoff reservoir. But generally a new tank can do this by hand-dosing. Note that some reef salt mixes may come in with mg higher than 1350 and alk a little higher than 8.3. This is ok. But the ratio I gave you is a good balanced relationship that will not be extreme in anything and will work well.

Now---just think positive coralline thoughts and get a good glass scraper. I am very fond of the Tunze Care Magnet cleaner, which cleans glass or acrylic (2 different blades) with a fierce magnet and yet avoids picking up sand grains which can scratch glass and particularly acrylic, nastily.

Old hands smile a bit when somebody says "Will this [urchin, asterina, snail, crab, etc] eat my coralline?" The answer is---you could only wish. Just keep that chemical balance I've outlined above and keep that algae scraper handy. Seriously. If you have an acrylic tank do not let any tiny pink dot stay on your tank wall AT ALL. Scrape it off. Coralline loves growing on glass/acrylic. It even prefers it to rock. Just keep scraping. The bits will reach the rocks and more and more will grow.

It can get so thick on the rock it looks as if somebody dripped purple ice cream on your rocks. When it's actively growing you'll see a scalloped edge of paler color around the edge of the growth. Will it suck up calcium? Oh, yes. Just do those tests and keep that balance up.

Do keep your tank temperature under 84 degrees. If it hits 85 under strong lights and stays there, your coralline will bleach white as snow, and take a long time to recover.

Keep the balance. Purple is in your future. Just don't let it grow on the glass.
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  1. New Comment
    I have some green spots on the walls and some purple on some rocks that I bought, but it just doesn't seem to be growing. I have high cal and alk but mag is around 1350. Temp stays around 76-79. Tank has been going since June. Years ago in the same tank it was covered with purple but I used city water with r.o and now I am on well water. I'm wondering if something in the well water is causing the coralline not to grow. The fish and nems are doing good.
    Posted 02/15/2016 at 08:13 PM by Bogue Chitto Bogue Chitto is offline
  2. New Comment
    vikinglord13's Avatar
    Why do you recommend not letting it growing on the glass? Does it damage the glass, or is it just harder to get off after it's established?
    Posted 05/21/2016 at 03:06 PM by vikinglord13 vikinglord13 is offline
  3. New Comment
    Sk8r's Avatar
    very, very, very hard to remove once it's been there a while.
    Posted 09/20/2017 at 09:02 AM by Sk8r Sk8r is offline

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